Features: This refractometer features high accuracy and easy operation. A professional measuring instrument, accurate test result. Easy to read by the clear calibration. Convenient to use, handle is comfortable to hold and non-slip. There are three types, cutting fluid testers in different ranges and salinometer that you can choose. Specifications: Option #1 #2 #3 Type Cutting Fluid Tester Salinometer Measuring Range 0-32% 0-20% 0-100 permille Minimum Scale 0.2% 0.1% 1 permille Length 17cm / 6.7inch Weight(approx.) 240g 219g 245g Instruction: 1. Open the cover and carefully wipe the prism with a soft cloth. 2. Take a few drops of the solution to be measured, place on the detection prism, gently close the cover to avoid producing bubbles which will make the solution spread all over the prism surface. 3. Put the cover directly point to the light source or bright place, observe the field of view through the eyepiece. 4. Turn the eyepiece to adjust the hand wheel to make the blue and white line clear. The scale value of the dividing line is the concentration of the solution. Note: 1. Please use this instrument according to the instruction, be careful when using. Do not loose any connection part arbitrarily, prevent violently shock, impact and falling off. 2. Use clean and soft cloth to wipe the instrument, do not put into water directly to clean and avoid scratch of surface. 3. Storage the instrument at dry and non-corrosive place. 4. Storage the part well. 5. The adjustment range of eyepiece and hand wheel is within 2cm left or right. Do not adjust it over 2cm, otherwise it will be broken. Package Included: 1 x Refractometer 1 x Screwdriver 1 x Pipette 1 x Clean Cloth 1 x Box