SNDWAY SW-B40 Laser Distance Meter Handheld Rangefinder Digital Mini Distance Measuring Meter Indoor Rechargeable Electronic Space Measurement Device for Length Area Volume Equipped with high-speed algorithm chip, this laser distance meter can deliver instant and precise measurement. It is capable of measuring length, area and volume. It can also be used for indirect measurement through Pythagorean theorem. It has mini size which makes it quite portable, widely used in construction industries, especially for large areas such as rooms, apartments, buildings, real estates, factories, etc. Features: Millimeter Precision - equipped with high-speed algorithm chip and upgraded lens, this meter delivers stable and precise measurement with accuracy of ±2mm. Capability - 0.1s quick measurement of distance, area, volume, indirect measurement through Pythagorean theorem. Practical Functions - unit switchable among meter (m), inches (in), feet (ft); auto-shut off in 150s. Stay Accurate - with self-calibration which allows users to calibrate the meter whenever necessary, with adjusting range from -9 to 9mm.  Rechargeable Battery - built-in rechargeable battery has a large capacity of 850mAh and can be easily charged via Type-C USB cable. Mini Size - it's small enough to fit in any jacket or trouser pocket, widely used in interior decoration, indoor design, construction field. Specifications: Brand: SNDWAY Material: Aluminium alloy Color: Black Model: SW-B40 / SW-B50 / SW-B60(Optional)   Model SW-B40 SW-B50 SW-B60 Max. measuring range 40m 50m 60m Laser color Red Reference point 2(rear, front) Accuracy ±(2mm+ d*10^-4) Continuous measure yes Area measure yes Volume measure yes Pythagorean measurement Full mode Unit options m/in/ft Working temperature 0°C~40°C Storage temperature -20°C~60°C Storage humidity 20%~80% RH Min/Max value yes Self-Calibration yes Laser level II Laser type 630-670nm,<1mW Automatically cut off laser 20s Automatic shutdown 150s Battery 3.7V 850mAh lithium battery Buttons/keys sound yes Item Size: 100.3 * 33.4 * 18.3mm / 3.94 * 1.31 * 0.72in Item Weight: 68g / 2.39oz Package Weight: 136g / 4.79oz Package Size: 16 * 9 * 3.5cm / 6.29 * 3.54 * 1.37in Packing List: 1 * Laser Distance Meter 1 * Carrying Bag 1 * USB cable 1 * User Manual (English)