Sennheiser SET900 Wireless Assistive TV Listening System The SET900 wireless tv headphones are easy to connect and use, providing exceptional audiophile-grade sound reproduction Adjust the headset volume to your preferred listening level with it's conveniently integrated volume control 50-16000 Hz-Max. Sound pressure level (active) 125 Decibels) IR (Infrared) wireless transmission with a range of up to 12 Meters Lithium-polymer rechargeable battery for 12 hours of continuous use 3 selectable hearing settings on the transmitter: optimized speech intelligibility due to switchable compression and treble boost Connectivity technology: wireless Excellent stereo soundindividually adjustable 3 selectable hearing settings on the transmitter Optimized speech intelligibility due to switchable compression & treble boost IR audio transmission for cordless mobility of up to 12 m 2 switchable microphones on the receiver pick up & amplify surrounding noise, allowing the user to hear ambient sounds