RCA RCA822C Wireless Outdoor Speaker 900MHz Transmitter and Receiver Indoor/Outdoor System Phase-Locked Loop (PLL) guarantees crystal clear audio from the speaker Automatic Level Controls (ALC) prevents sudden drastic changes in volume The RCA822C transmits an uninterrupted 900MHz wireless signal up to 45m (150ft) The 3-in-1 Power/Volume/Tuning button puts the essential controls in one place Tripod feet and water-resistant design makes the speaker natural for outdoor settings