Bosch GAM 220 MF Professional Angle Measurer for automatic calculation of single and double mitre angles without any other tools. A memory function allows for rapid calculation and transfer of angle, ideal for frequently used angle dimensions. Specifications: Measurement Range: 0-220°. Measurement Accuracy: +- 0.1°. Vial Measurement Accuracy: +- 0.05°. Accuracy of Angle Calculation: +- 0.1°. Power Supply: 4 x AA 1.5 V LR6 Batteries (supplied) Arm Length: 40cm. Weight: 1.3kg.