Never suffer from dual phone stress again. Whether we need an extra phone for work, or just for screening calls from mother, its not just the extra pocket clutter that drives us mad; its the varying ringtones, answering the wrong one, & the sheer last century-ness of it all. The ingenious Dual Sim Case allows iPhone 4/4S users to have two SIMs installed at the same time, suddenly this gadget seems indispensable! Use two SIM cards in one iPhone – just one click to switch between the cards. The case requires no software installation, no tool for switching between the two SIM cards, It accepts both standard SIM & Micro SIM cards. Simply activate the switch on the outer case to change the SIM in use. It couldnt be easier, or indeed more useful.