All iPhone models include written documentation, and a dock connector to USB cable. The first generation and 3G iPhones also came with a cleaning cloth. The first generation iPhone includes a stereo headset (earbuds and a microphone) and a plastic dock to hold the unit upright while charging and syncing. The iPhone 3G includes a similar headset plus a SIM eject tool (the first generation model requires a paperclip). The iPhone 3GS includes the SIM eject tool and a revised headset, which adds volume buttons (not functional with previous iPhone versions).