1. Relative/absolute measurement interchange at any position 2. Angle and slope readout conversion 3. Data hold 4. The display will turn off if you don't operate the device within 30 seconds,The product will automatic turn off if you don't operate it device within 3 minutes. 5. Compact and portable, wide application. Built-in Strong Magnets Measurement range:4*90° Accuracy: ±0.2 ° Resolution: 0.05° Battery type:2x1.5V "AAA" batteries (not included) Working temperature:0℃ - 50℃/32℉ - 122℉ Storage temperature:-10℃ - 50℃ Colour:Black Material:Plastic Package Contents: 1 * Angle Protractor Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.