Digital Hand-Held Dip-Type Refractometer, Type Pen-Wrestling. Measures Urine Specific Gravity 1.0000 To 1.0600, Accuracy +/-0.0010, Min. Resolution 0.0001%. Automatic Temp. Compensation (Atc) 10 To 35C, Measures In 2 Seconds. Zero Set W/Tap Water. For Hs Wrestling & Testing Urine.