The Sennheiser CI 1-N (article 005021) is the instrument cable that connects an electric guitar or bass to a Sennheiser evolution wireless bodypack transmitter, turning the transmitter into a wireless guitar system. One end has a standard 6.3 mm (1/4-inch) jack plug for the instrument's output socket, and the other end has a 3.5 mm jack with a threaded locking collar that screws into the audio input of the bodypack so it cannot be pulled out during a performance. It is the same cable Sennheiser supplies in its instrument sets and suits bodypacks from the evolution wireless range, including the SK 100, SK 300 and SK 500 series named in the listing. Guitarists and bassists, worship bands, theatre pits and rental companies keep a spare because a damaged instrument cable is the most common point of failure in a wireless rig. The cable is black and weighs about 54 g. It is sold on its own; the bodypack transmitter and receiver are not included. Sennheiser covers it with a two-year warranty.