Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limited to 2.5 milliwatts, giving it a very short range of up to 10 metres (33 ft). It employs UHF radio waves in the ISM bands, from 2.402 GHz to 2.48 GHz. It serves as an alternative to wired connections, and is mainly used to exchange files between nearby portable devices, to connect cell phones and music players with wireless headphones, wireless speakers, HIFI systems, or car audio, and for wireless transmission between TVs and soundbars.