General Tools MMD4E Digital Moisture Meter, Water Leak Detector, Moisture Tester, Pin Type, Backlit LCD Display With Audible
4.5 | 14,866 ratings
Price: 38.78
Last update: 01-30-2026
About this item
- HUMIDITY SENSOR: Our handy meter tool can quickly determine what level of remediation is needed to keep your family safe from black mold. High levels of dampness that go untreated are the leading cause of harmful fungus growth in the home.
- WATER LEAK DETECTOR: Finding the moisture content in your wood or drywall is the first step in early prevention. Continuously check and test suspicious water stains around the house so you can determine whether the area is wet or has already dried. Low, medium and high moisture tones and on-screen icons, Reading HOLD button
- MOISTURE READER: The mold test features large 0.3" high digits in a backlit LCD for quick and easy detecting. Our mildew scanner includes extra 8mm stainless steel pins, a protective cap that doubles as a calibration checker, and a “9V” battery.
- MOLD TESTER: For an accurate test read, stick the stainless steel pins into the surface of what you're measuring. The gauge has a broad range of 5 - 50% for wood and 1.5 - 33% for building materials such as concrete and drywall.
- GENERAL TOOLS: We're a recognized leader in designing and developing specialized precision tools dedicated to delivering exceptional customer service. We encourage artisans and DIYers to work smarter, measure better, and repair more productively.
Product information
Features & Specs
| Battery Description | Alkaline |
|---|---|
| LowerTemperature Range | 32 Degrees Fahrenheit |
| Mounting Type | Surface Mount |
| Upper Temperature Range | 60 Degrees Celsius |
| Voltage | 9 Volts |
| Temperature Accuracy | 3 Degrees Fahrenheit |
Measurements
| Item Dimensions W x H | 9.5"W x 1.4"H |
|---|
Additional details
| Color | Gray |
|---|
Warranty & Support
Amazon.com Return Policy:Amazon.com Voluntary 30-Day Return Guarantee:You can return many items you have purchased within 30 days following delivery of the item to you. Our Voluntary 30-Day Return Guarantee does not affect your legal right of withdrawal in any way. You can find out more about the exceptions and conditionshere.
For warranty information about this product, pleaseclick here[PDF ]
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General Tools MMD4E Digital Moisture Meter, Water Leak Detector, Moisture Tester, Pin Type, Backlit LCD Display With Audible and Visual High-Medium-Low Moisture Content Alerts, Grays
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Item details
| Brand Name | General Tools |
|---|---|
| Manufacturer | General Tools |
| UPC | 012301860924 716080037835 885312937219 885265551395 885367884865 681035414477 069060294668 031112659039 885898031110 522536779064 971483008299 031113382226 |
| Global Trade Identification Number | 00681035414477, 00885265551395 |
| Customer Reviews | 4.54.5 out of 5 stars(14,712) 4.5 out of 5 stars |
| Best Sellers Rank |
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| ASIN | B00275F5O2 |
| Item Type Name | Moisture Meter |
| Included Components | Moisture meter, batteries, extra pins |
| Item Height | 1.4 inches |
| Unit Count | 1.0 Count |
| Warranty Description | 1 Year |
Top reviews from the United States
- ChrisDecent UnitThe General Tools MMD4E Digital Moisture Meter is an indispensable tool for anyone dealing with moisture-related issues. From the moment I started using it, I was impressed by its accuracy and ease of use. Whether I'm checking for water damage in walls, floors, or ceilings, this moisture meter provides precise readings with just the press of a button.
What sets the MMD4E apart is its versatility and reliability. It features a wide moisture detection range, allowing me to accurately assess moisture levels in various materials, from wood and drywall to concrete and plaster. Plus, its compact size and ergonomic design make it comfortable to hold and use for extended periods.
Overall, the General Tools MMD4E Digital Moisture Meter is a must-have tool for contractors, homeowners, and DIY enthusiasts alike. Its accuracy, versatility, and ease of use make it an invaluable asset for identifying and addressing moisture issues quickly and effectively. I highly recommend it to anyone in need of a reliable moisture meter. - PatrickGreat technology for a great price!worked perfectly! Found a wet spot on wood and can now schedule a repair
- ErikGood if they sent a brand new one instead of someone returnWorks but they sent me an opened product not sure about battery life. Didn’t come with the instruction sheets so had to look everything up online.
- Mary in Northern MichiganBetter than Guessing... It's Science!I'm a potter with a wood fired kiln in Northern Michigan, and I have to know that my wood is dry, dry, dry: 15% (20% at the very most) moisture content. I've had 2 different moisture meters, and like this one best. It's accurate. Easy to read indoors and outdoors. I've dropped it several times; it didn't break or crack or start acting up. The batteries last a long time, are easy to change, and that little door that holds them in hasn't broken.
I originally got this to use at the kiln, but now I also use it to check the wood I heat my house with. No more guessing. The most important factor in getting a clean burn and maximum BTU's out of your wood is low moisture content. If that's important to you, get one of these gadgets.
Right price, good screen size, simple to use, accurate. - Brian MedleyNeat little gadget!Bought this moisture meter to keep check on the newly installed pressure treated deck rails. I know they say to wait months before staining but I read an article that says you can stain when the lumber is dry enough, 15% moisture content or below. So being impatient like I am I bought this meter. I checked the lumber after installing and it measured about 25% on average. 3 weeks later and it is about 20% on average. Won’t be too much longer hopefully! This thing is easy to use, easy to read and comes with an extra set of probes.
- hellolaniGreat product; it measures wood from 5 - 50% +/- 3% accuracyWe were getting hardwood floors installed - or so we thought - when the installers notified us that they could not do the installation because the wood in our house had acclimated to 6.4% moisture and our subfloors were at 12.8% moisture. The installer found a leak in our water softener line which we got fixed the next day. Unfortunately, we had no way of knowing (ourselves) when to call the installer back. Hence, we purchased this meter.
As far as we know, it works great. We aren't too concerned with the overall accuracy of the instrument, +/- 3% is just fine for us as we're looking to compare the difference between two materials in our home (assuming the error is consistent between those readings). The resolution of the meter is 0.1%.
Other things you might want to know:
- It comes with it's own 9v battery.
- It measures wood between 5 - 50% and 1.5 - 33% for other building materials.
- It has a hold feature which allows you to save the current reading so you don't have to keep the meter jammed in the material you are measuring.
- It beeps to let you know when it is done measuring. (Although, you can turn this off. We did accidentally and then figured out how to put it back on. We don't know why, but it has 8 different tones from which you can select.)
- It has a toggle button between measuring wood and concrete (or other building materials).
- The instruction manual is easy to read and follow. They come in English, French, and Spanish.
- It uses a two pin system to measure the electrical resistance of the material between the two pins. This is then calibrated against moisture content to give you the reading as a percentage. This means that it will make two small pin holes in the wood you are trying to measure. Therefore, if you are concerned about the holes, consider a "pinless" moisture meter, which are much more expensive.
The instruction manual lists other uses such as testing the moisture content of powders (for any scientists out there who need to measure such things for making standard solutions from scratch) and to test the dryness of a wall or furniture before painting or finishing. It also shows instructions for how to track down a leak using the meter. There's a funny picture in the instructions with the caption "be careful not to hurt your hands on the pins." Although, I did "test" the moisture content of my husband's leg. Don't worry, I didn't draw blood.
Overall, for the price, the features, and the product functionality (so far), I would say this is a great buy. Also, we got it shipped quickly via Amazon.com. It arrived two days after we purchased it. Yay!
UPDATE (7/31/2010): The pins broke when we were testing some brazilian walnut - one of the hardest woods out there. But I read in the instruction manual that pins were replaceable. I emailed General Tools through their website and got a quick email back. Less than a week later, I had two new prongs FOR FREE in my mailbox. Customer Service was AMAZING! The replacement prongs are much better than the ones that came with the meter. The new ones are shaped like little cones and have worked great on the harder woods.