... T7316E, M2008, M2616, i2002, i2004, M3903 & M3904 Telephones etc. and Desk Telephones with RJ9 / RJ22 Headset Socket CallTel Headset Model Number ... fit design for all-day use. Only compatible with telephones with a built-in amplifier. Some specific models: 3Com ... M7900, M8001, M8003, M9009, M9516 Powertouch 480 / 480e / 480i Telephones i2002, i2004, i2004IP (not compatible with i2400 phase II and ...