2 in 1 Digital Protractor - Measure not only length but also 360 ° angle (inside angle, outside angle). Locking Function Use locking screws to lock both feet in the desired position or angle desired. Large 1 " LCD display - LCD with electronic digital display, you can switch between degrees and minutes with " ° / " button The? Button? HOLD? stores the data during the measurement, the button? ON / OFF / Zero? resets the data to zero by briefly pressing any angle; Corner lock button for each angle. Length, width and precision - Length measurement: 400 mm; measuring angle: 000.0 ° ~ 999.9 °; precision ; ± 0.3 °; resolution: 0.1 °; measuring range: 0-360 °. The ruler body is forged from high quality stainless steel, ensuring quality, corrosion resistance and durability. Excellent Quality - Premium stainless steel forged scale is laser engraved (scale in mm and inches), resistant to abrasion and corrosion. High Quality Service - If you have any questions about usage, installation, and product, you can contact customer service at any time. We will solve the problem within 24 hours. The ruler may be a little sharp, please wear gloves when using it. Features: Length: 200 mm / 8 " Material: stainless aluminum Working range: 0-360 ° Angular precision: ± 0.3 ° Operating temperature: -10 ℃ - 50 ℃ Dimension: 28.7 * 11.18 * 2.779 cm Average battery life: 000h Weight: 300g Battery: 3V CR2032 battery