Axis I1400D Dual Channel Infrared Wireless Headphones: The IR1400D Is a Reliable and High-Quality Dual Channel Infrared Headphone System that Can Be Folded Away and Stored in The Included Hardcover Protective Carry Case The IR1400D is a reliable and high-quality dual-channel infrared headphone system that can be folded away and stored in the included hardcover protective carry case. Suitable for car audio systems and with an ultra-light design for comfortable wearing - wearers can enjoy premium-grade audio at any time! The system also features a Mini Jack for audio inputs like MP3, iPod, etc as well as auto mute and auto shut-off functions. Axis IR1400D Features: Automatic Mute & Shut-Off Function Mini Jack for Audio Input Ultra-light Design for Comfortable Wearing Axis IR1400D Specifications: System: Infrared Light (850nm) Speaker: 40mm Mylar Carrier Frequency: A Channel (Left Ch: 2.3MHz / Right Ch: 2.8MHz) B Channel (Left Ch: 3.2MHz / Right Ch: 3.8MHz) Input: Mini Jack for Audio Input Automatic Mute: Yes Automatic Shut-Off: Yes, after 10 mins of no signal detection Headphone Type: Compact, Foldaway Operating Distance: Up to 12 meters (maximum) Signal to Noise: >60db Channel Separation: >45db Distortion: