Klein MM400 vs MM600- Review and Comparison of the 2 Renowned Multimeters (2022)

So here are Klein MM400 vs MM600, head to head!

Klein multimeters are well-designed and measure standard values like the voltage, current, frequency, resistance, etc. with good accuracy. Klein brand has launched different models of multimeters each with different properties.

MM400 and MM600 are two popular multimetersOpens in a new tab.. Both have many similar features yet there exist differences. It can be confusing to select one of them if you do not know which multimeter is the best for you.

In this article, we have reviewed both models in detail, highlighting their key features, pros, cons, differences, etc., to help you select the right piece.

Product name ImageFeature 1Feature 2Price
Klein MM400 Digital Multimeter
Low battery indicatorLight weightClick Here for PriceOpens in a new tab.
Klein MM600Measures temperature in Celsius and FahrenheitEasily accessible battery compartmentClick Here for PriceOpens in a new tab.

Klein MM400 Digital Multimeter

Opens in a new tab.

Klein MM400 offers many features that are rarely seen in a tool of low price. It has a meaty body that is lightweight and fits well in the palm so you can use it single-handedly. It is good for general purpose use and ideal for those who are looking for a good-quality inexpensive multimeter.

It runs on 2 AAA batteries which are pretty inexpensive so you can replace them without worrying about their cost. A low battery indicator also lets you know the battery condition before it gets low completely. It displays temperature in two units; degree Celsius and Fahrenheit. It is designed by electricians so its features will fulfill your basic measurement-related needs.

You can measure different values like AC/DC voltage, AC/DC amperage, temperature, frequency, resistance, capacitance, and continuity through it. The range of capacitance and frequency is not as good as offered by the other multimeters but this issue can be ignored if you look at its low price.

  • Auto-ranging to provide accurate measurementsn Battery indicatorn 4,000-count display with backlightn Thermocouple in the same packagen Affordable price
  • Frequency and capacitance ranges are smallern Package lacks carry bag

Key Features of MM400

Opens in a new tab.

  • Measures voltage up to 600V
  • Measures current up to 10A
  • Measures temperature ranging from -18 degree Celsius to 538 degree Celsius
  • Measures frequency, capacitance, resistance, and duty cycle
  • CAT-III tested at 600V
  • Has a 1-year warranty
  • Comes with test leads, 2 AAA batteries, a thermocouple, and a user manual
  • Low battery indicator

Body and construction

Klein MM400 digital multimeter is made up of plastic which makes it light in weight and helps the operator have a stronger grip. It has a case and holster that provide the body with more protection. When you are handling different tolls at a time, accidental falls can happen at times. Klein MM400 can tolerate the effects of a 1-meter fall.

Rotating dial

The rotating dial of the Klein MM400 digital multimeter is meaty but still, you can manage it with your thumb easily. It is smooth and can select any of the nine options available.

The values you can select via this rotating dial are voltage, amperage, temperature, frequency, resistance, continuity, and capacitance. It also selects milliamp and microamp features. A rotating dial is present in the center of the body. So you will have equal access from the thumb no matter in which hand you are holding it.


This Klein multimeter has five smooth and rubber-made buttons. Their labeling is clear and easy to understand. Each button is used for its specific function. They perform tasks like turning the backlight on or off, selecting the range, and holding the screen to stop values from disappearing from the screen.


There are three jacks at the bottom of the body. They also have clear and understandable labeling. They are also used for plugging thermocouple that is used to measure temperature. The thermocouple comes with the meter in the same package.


Klein MM400 does not have a very high-resolution display. Still, it is good enough for the price. Values are easy to read through the LCD screen. The display is 4,000-count and has a backlight that is activated through a button. This feature comes in handy when you work in dark areas.


MM400 is a multi-purpose tool so you can use it to measure common values like voltage, current, temperature, frequency, resistance, capacitance, and continuity. The range of capacitance and frequency is small and it also lags sometimes.

You can measure AC/DC voltage up to 600V through this tool. AC/DC current can be measured up to 10A. The range of temperature is -18 / 538 degrees Celsius and 0 / 1,000 in Fahrenheit. You can measure resistance up to 40 megaohms and frequency up to 50 kilohertz. The measurements have good accuracy and you can rely on them for making day-to-day measurements.

Auto-Ranging- Save Yourself Some Time

The MM400 digital Klein multimeter can save you time in the field by auto-ranging, as it is a great feature. Setting the range of your multimeter can be a daunting task, and it’s one that not many people are experts in. That is why auto-ranging features exist – This function works by setting the range automatically instead of having to manually change it yourself, which can be tricky if you’re not too well versed in how these things work!


Safety and protection are very important factors that determine the usefulness and quality of a multimeter. The Klein multimeter MM400 has a CAT-III safety rating which is good enough for its price. It also has two fuses that provide input protection. It has an auto-off feature that protects the energy of the tool from being wasted.

Additional accessories for Klein MM400 Digital Auto Ranging Multimeter

MM400 is inexpensive and the good thing is the package does not only have a meter in it. It has additional accessories as well.

The accessories provided in the same package are 2 batteries that a multimeter requires to get active, test leads of standard quality, a thermocouple for measuring temperature in degrees Celsius and Fahrenheit, and an easy-to-understand user manual. The same manual can also be downloaded from the Klein website.

Klein MM600

When it comes to Klein MM400 vs MM600, Klein MM600 has more quality features than the MM400 multimeter but its price is also higher. It has a well-built and sturdy body structure. The main body is made up of durable plastic. That is why it can withstand the effects of 2-meter falls. It can also resist daily wear and tear due to regular use.

It has all the amperage scales available which professional electricians find very helpful and beneficial. Milliamp and micro-amp have their own dial positions as well. The tool, just like the MM400 model, has auto ranging feature. But this Klein multimeter also has a manual ranging option that comes in handy when you want to set ranges on your own.

Klein MM600 digital multimeter can measure temperature, frequency, AC/DC voltage, AC/DC amperage, resistance, capacitance, and continuity. They all have their dial positions. This troubleshooting tool can help you handle domestic as well as commercial electrical issues. It is affordable yet valuable.

Key features of MM600

Opens in a new tab.

  • Measures AC/DC voltage up to 1,000V
  • Measures AC/DC amperage up to 10A
  • Measures temperature in Celsius and Fahrenheit
  • Also measures frequency, resistance, capacitance, continuity, and duty cycle
  • Low battery indicator
  • Average RMS
  • CAT-IV safety rating
  • Size is 7″ x 3.5″ x 2.1″
  • Weighs 14.6 oz
  • Quality multimeter
  • Easily accessible battery compartment.
  • Comes with a low impedance mode for deterring ghost voltages.

Body and construction

Klein MM600 is constructed of plastic. It has a case and holster that add more protection to it. It can tolerate a six-foot accidental drop. There is a single compartment for the batteries and fuses. It is also easily accessible so you will not have to remove the holster to get access to the battery compartment.

Prominent parts of the body are a dial in the center, rubber buttons, jacks, and a large display. Labeling is also clear and neat. Operators enjoy using it as they can freely grip it in one hand. Here are some more Klein multimeter reviews.Opens in a new tab.

Rotatory dial

There is a meaty and circular rotatory dial in the center of MM600. You can handle it single-handedly due to its accessible position. It feels very smooth when it is moved. There are nine different dial positions. Each dial position activates a particular feature with the movement of the dial. The functions you can activate by rotating the dial are temperature, frequency, milliamp, micro-amp, current, voltage, continuity, capacitance, and resistance.


There are five rubber buttons on this meter. Each button has its own function and its labeling is also neat. One button is for setting range manually. Another button activates the screen hold feature. Through the screen hold feature, you can hold the readings shown on the screen for as long as you want. The Max/min button is also in the first lane.


Klein MM600 has four jacks in total. They also have neat and easy-to-understand labeling. The thermocouple is also plugged through these jacks.


The display is large and clearly visible. It is a 4,000-count LCD that has a backlight display to use when you are working in a dimly lit environment. The resolution of the LCD display is not as good as it should be. But it is still good for the price. It has a sampling rate of three times in a second.


MM600 has nearly the same functions as the functions of MM400 digital multimeter. The main difference in this MM400 and MM600 review is that the latter measures voltage up to 1,000V. Its continuity test also does not lag as much. It can measure temperature (-18 to 538 degree Celsius), frequency (10Hz / 500kHz), resistance (400Ω / 40MΩ), capacitance (40nF / 1000µF) and amperage (400µA / 10A).


It is well protected both mechanically and electrically. For mechanical protection, there is a rubber holster that keeps the tool safe when it falls. The rubber holster also provides protection against common wear and tear that happens due to regular use.

For electrical protection, it has a safety rating of CAT IV at 600V and CAT III at 1,000V. Other than that, there are HRC-type fuses inserted inside the multimeter to provide its internal circuitry protection and safety in the case of high voltage.

Additional accessories

Like MM400 auto ranging multimeter, the package of MM600 also has additional accessories. These accessories make the usage of this multimeter more convenient and easy for the operator. It comes with 2 standard AAA batteries. There are test leads and crocodile clips of good quality.

It also comes with a standard quality thermocouple which is required for measuring temperature in two different units. There is a small and soft carry bag, too. Klein MM400 does not have this bag. So, it is easier to carry and protect MM600 through the pouch for a professional electrician. Another additional feature is the easy-to-understand user manual. You can also download it from the website of its manufacturers.

Klein MM400 vs. Klein MM600 features

FeaturesKlein Tools MM400

Klein Tools MM600

CAT RatingCAT III 600V
CAT IV 600V / CAT III 1000V
Temperature DetectionYesYes
Low Battery IndicatorYesYes
Approachable Battery CompartmentYesYes
Test Leads Availability YesYes
Carrying PouchNoYes

Features of Klein MM400 auto-ranging multimeter and MM600 auto-ranging multimeter are very similar with a few advancements in the MM600. Below are the key differences in the features of these Klein multimeters.

Klein MM400 AC/DC voltage range

MM400 can measure AC/DC voltage up to 600V. It is considered a standard maximum value that is measured during general tests. The accuracy of AC voltage is ±(1.5%+5) and the accuracy of DC voltage is ±(1.2%+3).

Klein MM600 AC/DC current range

The main difference in the features of both models lies in the ability of MM600 to measure voltage up to 1,000V. It is considered fairly well. The accuracy of AC voltage is ±(1.5%+5) and the accuracy of its DC voltage value is ±(1.0%+3).

Continuity test

A continuity testOpens in a new tab. is performed to check whether the current is flowing in an electric circuit or not. Both models MM400 and MM600 are used for continuity tests. However, the continuity test of MM400 usually takes more time than the test of MM600. It also lags a lot which can be frustrating if you have to perform several other tests in a short time.


Both MM400 and MM600 and used to measure resistance. Their resistance range is also similar; 400Ω / 40MΩ. The accuracy of the resistance measurement is also the same; ±(2.0%+10).

True RMS/Average RMS

A tool that is True RMSOpens in a new tab. gives more accurate values than an average RMS tool. MM600 and MM400 both are actually average RMS.

Final Verdict: Klein MM400 vs MM600

Both MM600 and MM400 are affordable and very useful multimeters of Klein.

We also reviewed some of the best Extech multimeters on this page.Opens in a new tab.

Both are suitable for professional electricians as well as beginners. However, if you need a multimeter that can measure voltage up to 1,000 volts then MM600 is a better choice for you. Otherwise, MM400 is considerably more affordable with the ability to measure voltage up to 600 volts with accurate readings.

Recent Posts