Our main products are handheld refractometers, digital refractometers, gem refractometers, jewelry loupes and hardness testers. Our slogan is " Ability can be cultivated, details determine success or failure, attitude determines everything". Measurement Range:0-20% milk; Min.Divsion:0.2%. Made with the highest and finest quality of aluminum & rubber. Cushioned with soft & comfortable non-slip rubber. Uses ambient light only which means battery or power source is not required. Easy to focus and calibrate, accurate testing results guaranteed. Measurement Range:0-20% milk; Min.Divsion:0.2%. Made with the highest and finest quality of aluminum & rubber. Cushioned with soft & comfortable non-slip rubber. Uses ambient light only which means battery or power source is not required. Easy to focus and calibrate, accurate testing results guaranteed.