Password lock Easy to operate and very cost effective Backs-up and restores phonebook data from SIM card Supports data exchange amongst different SIM cards LCD-screen for viewing menu and backup progress Device independent, no PC or PDA Required Delete data function Capacity: CW-SB028A:8kb,250 group telephone numbers CW-SB028B:16kb,500 group telephone numbers CW-SB0286:16kb,250 group telephone numbers and 40 short messages Packing:Blister card 200pcs/carton