Overview: Switch between up to 6 cell phone numbers on the fly, without rebooting cell phone (must be cloned from original SIM cards first) English + Chinese STK menu languages (configurable)SIM cloning & phonebook software tools included USB SIM card reader + writer included Note: if you are new to SIM card cloning, DX recommends the new 2008-Edition 128K Magic SIM package for higher compatability & more advanced STK features. Specifications: Dimensions: 0.98 in x 0.59 in x 0.05 in Weight: 1.76 oz