Use a wireless headset or amplifier with your 2.5mm headset jack
This male 2.5mm to male RJ9 adapter allows the user to adapt any telephone with a 2.5mm headset jack to a wireless base station or a wired amplifier. Compatible with most standard amplifiers and wireless base stations
All Headset Buddy products are EU RoHS Compliant.
Compatible Phones:
Works with any phone that has a 2.5mm headset jack.
Altitouch
AT&T Synj, 992, 1080, 1070, 1040, 993
Cisco SPA921, 501G, 502G, 504G, 508G, 509G, 525G, 7920, 7921 7921G, 7929, Powercube
SPA 921, SPA 922, SPA 941, SPA 942, SPA 962
Nortel WLAN 2210, WLAN 2211
Panasonic 7600, 7700 and 300 series
Polycom SoundPoint IP 320, 321, 330, 331
RCA Executive Series, Visys