WL-2002 

Infrared wireless stereo headphone
Two channel
Ergonomic design for comfortable wearing
Auto mute and auto power off function on headphone
Carrier frequency:
a) A channel: 2.8MHz for right channel; 2.3MHz for left channel
b) B channel: 3.8MHz for right channel; 3.2MHz for left channel
Speaker: 40mm mylar
Effective range (maximum): about 10 meters
Power source: 2 x AAA batteries
Battery life: about 48 hours