Headphone Specifications FM System Carrier Frequency: R-CH 2.8MHz L-CH 2.3MHz Speaker: 40mm Mylar Cone Impedance: 32Ω 15% Effective Distance: Approx. 10M Power: AAA x 2 (PCS) Battery Life: Approx. 35 hours Weight: Approx. 160 g Transmitter Specifications Infrared Wavelength: 850nm Distortion: 0.20% Power In-Put Tolerance: 11V to 13V Audio Input Range: 0.1V~5V (RMS) Power: 12 DC/200mA Adaptor Weight: 85g Features -Fashionable and ergonomically designed with no stress consideration and light devise. -Hi-Quality transmitting and studio sound effects. -Foldable design for easy storage and portability. -With powerful echo effect for Karaoke practicing.