Works for AVAYA 1608 1616 9608G 9611G 9620 9621G 9630 9641G 9650... or CISCO 7902 7905 7906G 7911...7912 or Grandsteam GXP 14xx GXP1400 GXP1405 GXP2135 GXP2140 GXP2160...GXV3240 GXV3275 or Work for YEALINK T19P T21P T22P T28P T41P T32G T38G T42G T46G...T48G SNOM 300...821 Panasonic KXT and MORE DESKPHONES LISTED IN DESCRIPTION. SUPER SOUND QUALITY: Wideband Sound Wired telephone headset enables excellent sound quality for natural listening experience, features Noise Cancelling Microphone to reduce background noise for superior high quality sound, Acoustic Shock Protection Circuit to protect your hearing. MOST COMFORT HEADSETT: Ultra lightweight Wired hands-free RJ9 office Phone headset with adjustable headband to fit all head sizes, high quality and soft leatherette ear cushion enhance all-day wearing comfort. Professional Mic Mute / Scrolling Wheel Volume Control built in.