zCover CI821UDA-NA Desktop Dual Charger Set One Handset and Battery for Cisco 8821 Wireless IP PhonezDock CI821UDA Desktop Dual Charger Set for the Cisco 8821/8821-EX Wireless IP Phone charges your phone and a spare battery at the same time. The charger keeps your batteries charged, ensuring that your phone is ready for continuous use over an exten..