1.This honey refractometer is constructed with nonstaining noncorrosive and nonreactive chromium material which make sure hygiene and safety for all users. 2.It features quality optics with smooth focusing. Its main body is made of aluminum alloy. The internal optical lens with refractive index make up the precision optical system.The instrument is resistant to abrasion and corrosion, can be used to measure the general corrosive liquid. 3.The refractometer series are based on the principle that the refractive indices of liquids change when the concentration change. It's portable, easy, quick and no battery required, easier and more accurate than a traditional hydrymeters, more affordable than a digital meter. It's a tool for adult or young, home or professional use. 4.The refractometer comes with dropper, screwdriver, user manual and cleaning cloth, all included in a hard compact case, the item dimensions is 8'x3'x2', the item weight is only 8.6 ounces. makes it very portable and easy to carry.