I found the stated range of error to be ambiguous. It was stated as being within 3% of the reading. But the units of measure of the reading are themselves in percent.So I wrote the following to the manufacturer, asking if I had a reading of, say, 10% did that mean the range of error was 9.97 - 10.03% or 7 - 13%.This was their reply:The accuracy is ±(3% + 3 digits) as stated in the manual. To use your example, if the meter reads 10% then it is really between 7%-13%. The website will be updated accordingly. Thank you for bringing this to our attention and if there is anything else you have questions about, please feel free to contact us.

Can I use this product to rule out a plumbing leak under my concrete bathroom floor. The outer bathroom wall is concrete & paint is bubbling.

It won't show thru the cement unless it is wet. Also is the wall an exterior wall & you could be getting moisture there. With the paint bubbling you do have a water problem from some where inside or out, but you could check with the tool on the inside in the wall real low next to the cement. It worked real well for my particular problem without tearing up the carpet to find my problem. Hope this helps.

I have a wooden floor that is swelling little bit. I know I had a small water leak. Can this tool help me to check if there is moisture underneath?

ABSOLUTELY! This is just what you need, it tells you the exact moisture where the contacts touch the wood. There is a small button on the face right under the word GENERAL that allows you to pick wood or concrete. I use it on our Maple flooring in the summer to see where we are with water content.

Will it measure moisture in drywall?

Yes. It has two features (1) Wood which I use on dry wall, wood, plastered walls, carpeting.. (2) Building material which I use on concrete floors, concrete blocks... I have found it works well on concrete and I can trace moisture in our basement floors which has helped to target where work needs to be done in outside grading. By the way I am a 78 year old woman and have had "fun" using this meter. Money well spent.

Desertcart Logo

Deliver to Faroe Islands

For best experience Get the App

DOWNLOAD THE APP

WE SOURCE ITEMS FROM

UAE
UK
India
USA
Japan
KOREA

Customer Services

About Us

Customer Support

Description

💧 Stay ahead of leaks and mold—because your home deserves the best defense!

DURABLE READY TO USE - Includes extra stainless steel pins, protective calibration cap, and 9V battery for immediate, reliable operation.
USER FRIENDLY INTERFACE - Large backlit LCD with 0.3" digits and hold button ensures quick, accurate readings anytime, even in low light.
TRUSTED BY PROS DI YERS - Ergonomically designed, CE approved, and backed by General Tools’ legacy of precision and quality.
INSTANT LEAK IDENTIFICATION - Detect hidden water leaks early with clear high-medium-low alerts to prevent costly mold damage.
PRECISION MOISTURE DETECTION - Pinpoint moisture levels from 1.5% to 50% for wood, drywall, and concrete with ultra-sensitive sensors.

The General Tools MMD4E Digital Moisture Meter is a professional-grade pin-type tester designed to accurately measure moisture content in wood, drywall, and concrete. Featuring a backlit LCD with large digits, audible and visual alerts, and durable stainless steel pins, it enables early detection of water leaks and mold risk. Ideal for home inspections, construction, and restoration, it comes ready to use with batteries and extra pins, ensuring precise readings and peace of mind.

Specifications

Color	Gray
Brand	General Tools
Product Dimensions	9.5"W x 1.4"H
Battery Description	Alkaline
Lower Temperature Rating	32 Degrees Fahrenheit
Mounting Type	Surface Mount
Upper Temperature Rating	60 Degrees Celsius
Voltage	9 Volts
Temperature Accuracy	3
Manufacturer	General Tools
UPC	012301860924 716080037835 885312937219 885265551395 885367884865 681035414477 069060294668 031112659039 885898031110 522536779064 971483008299 031113382226
Global Trade Identification Number	00681035414477, 00885265551395
Part Number	MMD4E
Item Weight	3.98 ounces
Item model number	MMD4E
Batteries	1 Product Specific batteries required. (included)
Is Discontinued By Manufacturer	No
Size	Pin Type
Style	Digital Pin Type, Visual & Audible Alerts
Pattern	Digital Moisture Meter
Shape	Drywall
Power Source	Battery Powered
Item Package Quantity	1
Measurement System	Metric
Usage	Inside; Amateur, Inside; Professional
Included Components	Moisture meter, batteries, extra pins
Batteries Included?	Yes
Batteries Required?	Yes
Battery Cell Type	Zinc Carbon
Description Pile	Alkaline
Warranty Description	1 Year