4-in-1 Antifreeze Refractometer Coolant Tester for Automobile Antifreeze Systems, Battery Acid, Ethylene and Propylene Glycol

Tried the test strips but found they were very vague in their testing. This tool quickly gave me a precise, no doubt reading of the antifreeze level in my boiler system. Good value and accuracy.

Results are easy to read

I bought 2 of these. One is for my son. One came damaged and is going to be exchanged. The instruction booklet say nothing about the scales or how to read them. As another review mentioned, the pictures don't correspond with the calibration instructions. My primary need is for testing DEF for my RV. I read on a forum that some nasty soles like to buy DEF at Walmart and return the container filled with water. This will do major damage to the DEF system of the unlucky person who gets stuck with it. I don't want to be that person.The replacement instrument came today. I bought some distilled water and checked the calibration of each. Both are set to zero upon arrival.One word of caution. Make certain the test area is saturated under the window. No air gaps. I had to hold the test area level to get the drops to disperse correctly and fill the test area.Seems like a well made tool/fragile instrument.

I've never used one of these before and I was afraid that it being a good price it would be cheap. It is well made, has a nice plastic case, an included screwdriver to adjust it, and a microfiber wipe to clean the glass plate. Right out of the box it was lined up perfectly using distilled water. It was absolutely accurate and I'm glad I made this purchase.

This works great and easy to use. Definitely recommended for your tool box!