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 optics solid tester lightweight comes with all you need and case

When I got it out of the box and looked through the lens the scales weren’t clear. Had to take the viewing lens off and clean the scale lens. This was difficult due to how small it is and the depth in the tool. After cleaning the scale was now visible and I was able to check calibration. In fairness I’ve not tested any of the fluids yet other than straight water for cal. I will update when I use it.

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.

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.

I recently had to add water to my truck's cooling system to continue to drive it until I could get some antifreeze. I bought full strength antifreeze rather than the 50-50 type since I knew I couldn't drain the all weak water/antifreeze mix that still remained. After draining all I could I added pure antifreeze to the remaining coolant and with the help of this tool I got a perfect mix. Although it reads in celsius doing the conversion to fahrenheit is easy so it doesn't present a problem for me. It can also check the windshield washer fluid if I have been using a summer mix and then transition to winter mix.

It works easy to use, I can’t confirm accuracy but it’s better than the floating ball type .

Mejor de lo esperado

Tools like these (refractometer testers) used to cost over $100 back 10-15 years ago but FFW today with the myriad of products from you know where, from all kinds of "brands" on Amazon, now you can get one for a fraction of the price--nice! These work by measuring the speed of light through the liquid placed on them, rather than the specific gravity or density of the fluid, as do old-skool hydrometer (float) testers. As a result they are more reliable across different coolant types (or what have you) and more accurate in general. This was my first time using one and I will say it's a little tricky at first. If you read the manual you'll find they first tell you that you need to calibrate it. Well I tried doing this and it seems the distilled water likes to not "stick" as well to the glass plate and getting enough on there and it to stay there and completely cover the plate was...a bit tricky as said. You see, you need to sandwich that liquid with the cover *and* there can't be any air bubbles or areas of the plate not covered. In the end, after a few tries, I got it but it seemed to be a waste of time since it seemed properly calibrated already--it actually took me a while to even figure this out--that the "line" was already at zero and I didn't have to adjust anything. **NOTE: The front of the barrel just after the eye piece is a focus adjustment. I recommend you adjust that *before* you do anything else since trying to adjust that after you've put fluid on it is just going to rock it back and forth which might upset the liquid on the plate.** After that I moved on to actually testing coolant. The coolant I mixed myself because I refuse to buy the grossly overpriced 50/50 "premix" stuff, though it's getting hard to get concentrate these days--another story. Need a tester to make sure of the mix and what is in the car after a coolant change. Coolant "stuck" to the plate a lot better than the pure water and it was much easier to get the fluid to both stay there and "sandwich" properly with complete coverage. As said I should have just skipped the "calibration", which I imagine a lot of ppl given "nobody reads instructions" lol. Sure enough, coolant was showing -38C dead on--coolant bottle says 50/50 should net -37C so that was close enough for me to consider it good...both the coolant and the tester! Easy peasy and highly recommended for use on modern day coolants of which every manufacturer has their own type/blend all of such variances affect the accuracy of the float-type hydrometer testers. It of course has scales for a few other things (DEF, battery acid, etc.)--I didn't test those but trust it will be easy/accurate.

Working great and giving you true information about the Coolant water

Fonctionne bien

Only used it once, was easy to use and was able to get a reading quickly.