Review on SMARTSMITH Alcohol Refractometer - High Accuracy Spirit Alcohol 🍹 Volume Percent Measurement with automatic temperature compensation (ATC), 0-80% v/v Range by Amy Hernandez

This block seems very precise and easy to read. I checked the calibration with distilled water and it showed a perfect 0 right out of the box. I knew my car wasn't at 50/50 after a flush and prime, but I wanted to know exactly where it was. My test reading showed -28F, so I have a concentration of around 46%. It also makes windshield wiper fluid and battery acid, but there's no guide detailing all the scales. It's pretty basic, but if you're not familiar with everything you need, you can find the information elsewhere. The instructions simply tell you how to calibrate the test solution and apply it to the window. Nothing about heat exposure, cleaning other than wiping with a clean, soft cloth, or what all the scales are for. I think this could be a 5 star product but they should give you more detailed instructions so you can get 5 star results.