4-in-1 DEF Antifreeze Coolant Refractometer for Automobile Antifreeze System, Diesel Exhaust Fluid, Battery Acid and Windshield Washer Fluid

I bought this 4-in-1 DEF Antifreeze Coolant Refractometer to check my antifreeze mix, and it works perfectly. Super easy to use right out of the box—just a drop of fluid and you get an instant, accurate reading. The numbers are clear and easy to read, and it even covers DEF and battery acid checks. Feels solid and well-built. This tool takes all the guessing out of coolant testing—highly recommend for any car owner or DIY mechanic.

Very hand to have if you have a diesel truck that uses def works great to measure to make sure it is inspect

Great product. Easy to use. And well worth the money to keep on board my RV. Used distilled water to test the unit when it arrived. It was perfectly calibrated. Next, I extracted a few ounces of DEF from the tank on my RV. That, also, showed a perfect ammonia level.

The refractors were delivered to the client. We have not received any negative feedback from the client regarding the product. Therefore, at this time, the refractors served the purpose.

Highly impressed with this tool. Calibrated using distilled water, it was *exactly* on the waterline. Then tested a fresh jug of Prestone 50/50, the reading was minus 34 degrees, which is what Prestone claims for their product. Spent the rest of the evening testing the coolant on all of our vehicles & equipment. We live in the frozen north, and regularly have 30-40 below zero in the wintertime. Cannot afford a cracked block or a frozen radiator. Had several of the older style testers which relied on floating balls or a floating pointer. Hated them, they never give the same reading twice, so how can you possibly trust the test results? All of them went in the trash. I'll *never* use anything but the Refractometer from now on. Definitely going into the current winter with peace of mind.

I used it for testing antifreeze. Unlike chip and inaccurate hifrometers, this is reliable tool that gave me consistent result. High quality and easy to use.

I use this to check cars and motorcycle fluid and works very well

For the price, this is very accurate. 10/10