Features: 1) Show SIM1 or SIM2 number on screen 2) Both numbers can be on line at the same time 3) No data lose when switching 2 numbers or turning off/ on the mobile 4) Super slim design with special general dual sim card IC for stable quality 5) Cut SIM Card into specialized size to fit into the General SIM Card holder 6) Support almost all GSM mobiles 7) Super slim design with special general dual sim card IC for stable quality 8) 6 months guarantee(Man-made fault, neglect of use shall not be covered in the guaranty