Features: Wireless tour guide system receiver with earphone, 50 meters effective range. UHF 432.5-433.5/ 433-434MHZ frequency band, preset 2 optional channels. Independent volume control helps you adjust the receiving volume freely. PLL frequency synthesis technique for stable signal transmission. Low power consumption design for long time usage. With a backside clip for fixing it onto the top of trousers. Suitable for wireless tour guiding, simultaneous translation, audio-visual education, etc.