A number of Alpina watches feature high-quality selfwinding mechanical movements. The noiseless rotor inside an automatic watch converts your forearm's every motion into energy that winds the mainspring. When fully wound, it provides the watch with a power reserve of about 40 hours. Provided it is worn regularly and actively, the watch should never require manual winding. Should it remain off the wrist for some days, the movement can be wound manually. Wind the movement by turning the crown clockwise approximately 15 full rotations. Push the crown back in. If a screw crown, unscrew the crown by turning the crown counterclockwise. To lock a screw crown, push the crown into the case and turn clockwise until it is tightly screwed in place.