The Apple Watch is available in multiple variants, distinguished by different combinations of casing and interchangeable bands. The latest watch is available in two sizes: 40 mm (1. 6 in) and 44 mm (1. 7 in), replacing the 38 mm (1. 5 in) and 42 mm (1. 7 in) sizes on previous models. The design of the watch has not changed significantly since its release, so customizable bands and accessories are typically compatible with any Apple Watch of the associating size (38 mm (1. 5 in) matches 40 mm (1. 6 in) and 42 mm (1. 7 in) matches 44 mm (1. 7 in)). The casing of the watch includes a mechanism to enable the straps to be interchangeable. For input, the watch includes a "digital crown", which can be turned to scroll or zoom and pressed to return to the home screen, and a touchscreen that features Force Touch technology, which makes it pressure-sensitive and capable of distinguishing between a tap and a press. The watch also has a side button which can be used to display recently used apps and access Apple Pay. Apple rates the device's battery for 18 hours of mixed usage. Apple Watch is charged by means of inductive charging, using a cable similar to the MagSafe cable from Apple's MacBook family of laptops. If the watch's battery depletes to less than 10 percent, the user is alerted and offered to enable a "power reserve" mode, which allows the user to continue to read the time for an additional 72 hours. The watch then reverts to its original mode when recharged.