Product info: Super ghost sim - NEW FEATURE! Switch between sims via the phone's menu! - NEW FEATURE! Option to auto switch between sims every 1-99 minutes - works with all makes and models - use the manual sim selection option if you don't want to auto switch - allows you to use two sim cards in one phone - more convenient than removing your back cover/battery every time you want to swap sim cards - combine business/personal lines and address books on one handset - switch between networks easily - no more coverage problems! - take advantages of cheaper rates from different phone companies - saves your previous calls, received calls, time and date settings etc. - sits in your normal sim slot - no need to replace your phone's back cover - the ghost sim goes in your normal sim slot - works with all sims (including 3) - can be used to add another 200 contacts to your phone book via the second sim card (sim dependent) - also known as dual sims/twin sims How they work: the product fits into the sim slot on your phone with your two cut down sim cards inside it. When you turn on your phone you will be prompted to select the network or sim you wish to use. Your phone then operates as usual but allows you to switch between two sims without removing the battery and back cover first. To alternate between sims select the option in your phone's menu (the product adds this function to your menu). The phone will display the "insert sim card" message for a few seconds then swap over to the other sim. Click here for a complete guide on use