The Express audio keypad is the worlds first Wi-Fi keypad for Sonos. Xpresscan be set up in minutes using the iPort iOS app. Functions include play/pause, track forward, volume control and toggle capability through sonos favorites. Wherever you have Wi-Fi Express will be able to control your music. Xpress has a rechargeable lithium polymer battery that lasts 4-6 months with normal use and Will magnetically mount anywhere. If you want to mount Xpress on a non-metal surface, Use the stick-on mount included in the box. The Express audio keypad is an endorsed partner integration with sonos.