Specifications:
FM system carrier frequency: R-ch 2.8 MHz / L-ch 2.3 MHz
Speaker: 40mm mylar cone
Impedance: 32 Ohms±10%
Effective distance: 10 meters(max.)
Power source: DC 3V (2x1.5V AAA batteries)

Features:
Light weight design for wearing comfort
Auto muting on headphone
Auto power off when no signal
Volume control and on/off switch on headphone
Mono/stereo switch on headphone