An accurate and economical tool for ensuring proper levels of glycol treatment in HVAC fluid systems. Removes guess work and prevents wasteful over-treatment. An essential tool for any glycol treatment job. All Glycometers have a metal body w/ cushioned eyepiece, focus adjustment, and a rubber hand grip. Included with each is a calibration screwdriver and calibration fluid, a plastic pipette, optical cleaning cloth, and a rugged carrying case.The Glycometer is a glycol refractometer for measuring anti-freeze levels of propylene glycol or ethylene glycol in HVAC systems.