The Palm Abbe is fast, convenient and easy to use. The two button interface makes it user friendly; one button takes the reading while the other allows you to step through various menu options. Simply place a drop or two of fluid in the titanium well using the plastic eye dropper and press the Go button. Nonlinear temperature compensation is automatic and insures that fluids read between 0 °C and 50 °C ( 32 to 122 °F) are measured accurately Calibration is automatic and does not require the use of special calibration solutions or tools. Add the Rubber Armor Jacket (HH-688 sold separately) to your Palm Abbe to protect it from scratches and give you a better grip. Purchase our Rugged Plastic Case (HH-686 sold separately) for added protection when storing, the case is water-proof and crush-proof. Requires 2-AAA batteries, included.