The Beurer Speedbox II with 2D-sensor-technology. The personal trainers for hikers, walkers and runners. More than 200 hours training possible. Simply and safely secured without unfixing shoe lace. Continuous recording of the foot acceleration in two dimensions; Trouble-free digital data transfer; Records distance in km (granduation in 10m steps); Actual speed; Target time and target distance settable. Switch between km/h (mi/h) and km/min (mi/min); Can be calibrated to match individual running style; Deviation on 10km distance: 0 - 300m (calibrated), 0 - 500m (non-calibrated), Watertight housing (30m). Automatic activation by tapping on with the foot; Including battery (3V Lithium CR2032); Easy battery change; Battery-service life trebled: 200 hours training at 20C possible; Only compatible with specific digital Beurer heart rate monitors. Size H20, W3.8, D17.3cm. Weight 0.17kg. Batteries required 1 x C (included). Manufacturers 2 year guarantee.