Review on Brix Refractometer with ATC - Dual Scale for Wine Making, Beer Brewing, and Homebrew Kit: Specific Gravity & Brix Hydrometer by Nicole Harty

This is literally an identical device being sold for double the price in some online breweries. It is excellent for testing non-fermented solutions. It has been calibrated to 0 with distilled water and agrees with my hydrometers by 40 points. The focus ring works, the numbers are clear. The blue/clear transition is clear enough for accurate readings. Other reviews indicate inaccuracy compared to the hydrometer when using partially or fully fermented foods. That's right, they don't read straight away when there's alcohol in the solution because they're two completely different methods of measurement. You'll need to use an adjustment calculator when alcohol enters the equation, and there are several options for a quick search online. Example: 10 Brix is 1.0405 Brix - 1.020 is half, hydrometer reads 1.007 and is probably almost done. They're great for quick readings early in the process without the need to quickly chill the wort, or for temperature corrections when you want to make quick adjustments. At the end of the process it never hurts to check with a hydrometer or calculator or both from time to time.