Enjoy rich sound indoors or out - with this brand new 3 in 1 (Wireless Headphone, Wired Headphone, RM Radio Receiver) Hi-Fi FM Wireless Headphone! RECEIVER DC 3V (2×1.5V AAA BATTERIES) POWER SUPPLY TRANSMITTER DC 3V (2×1.5V AAA BATTERIES) AUDIO IN FREQUENCY RESPONSE 20-20,000 Hz DISTORTION <2% THD S/N RATIO 50 DB RECEIVE FREQUENCIES 88-108 MHZ MODULATION FREQUENCY MODULATION (FM) OPERATION DISTANCE ~30 METERS 360º Total Price