Features: ★ Professionally measure the inner and outer angles and angles of objects ★ 0-360 ° complete measurement. ★ Easy to lock at any angle, compact, accurate measurement, easy to read. ★ With a locking knob, convenient to lock the angle at any position. ★ 5 minutes automatically shut down, induction automatically boot. ★ Button function: open / key, clear key, data hold button, degree and degree conversion button Material:Carbon fiber + ABS Specifications:0-200mm,0-300mm. Measuring range: 0-360 ° Resolution: 0.1 ° Accuracy: ± 0.3 ° Working power: 3V Battery model:1*CR2032(not included) Operation time: 5,000 hours Operating temperature: 0 °C - +50 °C Working humidity: ≤85% Automatic closed screen time: 6min Usages: Measurement of angle and length Battery: 3v cr2032( Not included) Angle Detector Packing includes: 1* 2-in-1 Digital Angle Ruler.（Without battery） Steel Ruler Packing includes: 1* Stainless steel ruler