RCA Wireless Headphone CWHP140 Slightly Used Product Details: • Transmits audio signal up to 150 feet, through walls, floors and ceilings • Phase-Lock Loop (PLL) technology locks in frequency to prevent signal loss • 40mm speakers for outstanding sound performance • Headphones charge on transmitter for easy storage and use • 900 MHz transmitting frequency • Compact, comfortable design provides full, rich sound without the bulkiness of most other full-size headphones • 100-120 input volts