"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 "HOLD" button stores data during measurement, "ON / OFF / Zero button ?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, which guarantees quality, corrosion resistance and durability. Excellent Quality - Premium stainless steel forged scale is laser engraved (mm and inch scale), abrasion and corrosion resistant. 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