So you went ahead and purchased a brand new iPhone 4 and then realized that you also need another device to make calls. Of course, you can always transfer your SIM to another phone when you have to make that all-important call. But it is tricky. The Apple iPhone 4 uses microSIM which is not compatible on most of the other mobile phones in the market.
Thanks to the accessory manufacturers, we now have a microSIM adapter. What this product actually does is it lets you fit your tiny microSIM into the slot so that you may use this larger mini-SIM sized adapter on any of the other mobile phones.