$21.99 Refractometer for Battery, Anti-freeze, and DEF
Check out this $21.99 refractometer on Amazon. Lotta bang for the buck. Received it yesterday. Seems reasonably well-made and appears to work as advertised.
Forum Discussion
Makes sure you clean it with water after using it. Especially with def. Also make sure it is calibrated. I have never used a cheap one like that so I'm not sure how accurate it will be. There should be calibrating instructions that came in the box.
