the controller. Whenever the controller senses a change, it sends a signal to the microprocessor, which performs the desired action. The faster a finger moves around the wheel, the more concentrated the stream of signals it sends out. The moment the finger leaves the wheel, however, is when the controller stops detecting change in capacitance, therefore stopping the current process. Similar technologies The Creative Zen Touch from 2004 has a vertical scroll wheel similar to the iPod's click wheel. That same year, the luxury Nokia 7280 mobile phone also featured a scroll wheel. The Samsung SGH-i300 from 2005, as well as Motorola ROKR E8 from 2007, also have it. In 2007, Nokia created the 'Navi wheel' which debuted on the Nokia N81. LG also implemented such a feature on its LG Chocolate (VX8550). Several models of Sony Walkman music players also have similar interfaces. References External links Click wheel