Features: Easily readable LCD display shows the exact angle at once. Automatically shut off after five minutes to prolong the batteries& 39; life. Backlight design: keep its normal use on dark light. Data holding function: Help the use on dark light. Mechanical lock(Lock knob): Keep the angle invariable in the process of line or measure the angle. Low power alarm, notify you the power in advance. s: Measuring range: 0~225 Increase/decrease angle: 0.1 Measuring range: 0~225 Measuring precision: 0.5 Working temperature: 10C~+50C Battery: 9V 6F22 Specifications: Material: aluminium alloy Color: white Length: 400mm Size:430*60*30mm Package Includes: 1 X Angle Instrument CAUTION: 1. Do not move the screws and components at random. 2. Please handle your angle meter with care, use even strength to rotate the Rotate Arm, and do not use too much strength. 3. Dont keep the backlight open for a long time. 4. When the low power Alarm icon appears on the display, please change the batteries