Comdio 2.5mm Call Center Telephone Headset with Mic + Volume Mute Controls for Polycom IP320 IP321 IP330 IP331 SoundPoint Pro SE-220 Zultys Technologies: Zip 4x4 Zip 4x5 IP Phones (H103VP2)

Direct connect telephone headsets(2.5mm stereo plug) with noise canceling are ideal for most standard telehpones equipped with standard 2.5mm headset port. You can plug them directly to a 2.5mm headset jack on most basic and business phones such as Polycom Cisco Linksys SPA, Panasonic Zultys AT&T Aastra GrandStream and many many cordless DECT phones with standard 2.5mm Headset Port.
Works for Phones:
Cisco Linksys: CIT200, CIT300, CIT310, CIT400
Cisco 7985 IP phones
Cisco SPA303, 501G, 502G, 504G, 508G, 509G, 525G 512G 514G,525G2
Cisco LinksysSPA921, SPA922, SPA941, SPA942, SPA962 models
PolycomIP320, IP321, IP330, IP331, SoundPoint Pro SE-220 SE-225
GrandstreamGXP-2010, GXP-2020, GXP-2100, GXP-2110, GXP-2120, GXP-280, GXP-285, BT200, BT201 GXP-2000(Version 1.0 higher with 2.5mm Headset Socket)
PanasonicKX-NT136, KX-NT343, KX-NT346, KX-NT366 ,KX-T 7603, KX-T 7625, KX-T 7630, KX-T7633, KX-T 7636, KX-T 7730, KX-T 7735
GigasetC610 IP, C620H
Zultys Technologies: ZIP 4x4, ZIP 4x5 IP Phones