1. Relative/absolute measurement interchange at any position; 2. Angle and slope readout conversion; Data hold; 3. built-in Strong Magnets 4. The display will turn off if you don't operate the device within , The product will automatic turn off if you don't operate it device within 3 minutes. 5. Compact and portable, wide application. Measuring range: 4x90 Resolution: 0.05 Accuracy: 0.2 Repeatability: 0.1 Battery: 3.7V 400mah Working temperature: -10 to 50 Magnetized bottom makes stick-on measurements simple and accurate; Absolute zero measurement based on the level surface; size: 62.2 x 62.2 x 32mm Material: ABS colour: Black Package Contents: 1 x Angle Protractor 1 x charging cable 1 x English instructions 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.