The WMS40 Mini Single Instrumental Set is a true plugnplay wireless solution providing crystal clear audio sound. The included PT40 Mini pocket transmitter provides a professional 3pin mini XLR connector, compatible with guitar and bass levels, headsets and instrumental mics. Its extremely long battery life of 30 hours off a single AA battery saves money in day-to-day use. The receiver comes in an ultra compact housing and offers a 1/4" jack output. The WMS40 Mini system_s new frequency options include US25A 537.500 MHz, US25B 537.900 MHz, US25C 539.300 MHz, US25D 540.400 MHz.