Even as market contemporaries are transitioning from standard to micro-SIM at a snail's pace, a minority of smartphones use nano-SIM (4FF) form-factor. It looks like Motorola's upcoming Moto X smartphone is one of them. It was pictured with its external nano-SIM tray popped out. While it's fairly straightforward to cut standard SIM cards down to micro-SIM dimensions, converting a standard SIM to nano-SIM is a lot more tricky, making your SIM a lot more prone to damage; warranting a trip to the nearest ground outlet of your carrier, where they'd be more than happy to cut your SIM down. The upside, though, is extremely low device volume spent in holding a SIM card. The external tray saves up space inside the device, compared to conventional SIM locks.