The 2.5mm plug is used for following IP Phones:
- For C isco SPA 501G, 502G, 504G, 508G, 509G, 525G
- For C isco Linksys SPA921, SPA922, SPA941, SPA942, SPA962 models
- For Polycom IP320, IP321, IP330, IP331
- For Grandstream GXP-2000, GXP-2010, GXP-2020, GXP-2100, GXP-2110, GXP-2120, GXP-280, GXP-285, BT200, BT201
- For P anasonic KX-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
- For Gigaset C610 IP, C620H
Your RJ9 headset should be compatible with below telephones.
Please see compatible models below.This list is not all inclusive
Aastra/Packet8/8x8
AltiGen IP Phone
Avaya 4600 Series IP
ESI 48-Key IP Feature Phone and 48-Key Digital Feature Phone
GE Model 2-9451
Inter-Tel
Mitel IP
N E C
Norstar
Nortel IP 1120E IP, 1140E IP, 1150E IP, i2002 and i2004
Nortel IP - 1230
Nortel Meridian Norstar Northern Telecom: T7316, T7316E, M7310, M7208, M7308, M7316, M7324, M7900, M2216, M3903, M3904, M3905, M5208, M5209, M5216, M5317, M8001, M8003, SL100, model NTZK23AA, AB: (M2216):ACDI
3 Com:
3102 &3103 Telephones
Aastra:
2465,2564, 480e,480i,,53i,55i,57i,57iCT,6753i,6755i,6757i, 9112i,9133i,9143i,9480i
M4000, M4020, M5208, M5209, M5216, M5317,
M7900, M8001,M8003,M9009,M9516,
Powertouch 480/480e/480i Telephones
,i2002,i2004, i2004IP(not compatible with i2400 phase II and i2004 POE phones)
Alcatel-Lucent:
4004,4020,4022,4035,4037 Telephones
AltiGen phone Models:
500,510,600,705,710,720
Ascom:
Berkshire 200, 400, 600, 800, SD30, MR30, MR51, MR61
AVAYA / Lucent:
6402D, 6408D+, 6416D+M, 6424D+M, 8403, 8410D, 8434DX
4406D+, 4412D+, 4424D+, 4424LD+
2410, 2420
4610, 4620, 4621
5410, 5420
5610, 5620
DT1, DT3, DT5
Cable & Wireless:
CWB 100H, CWB 200H, CWB 500, CWB 600
Comdial:
8312 8412
Commander NT40:
Commander NT Economy,Standard,Advantage, Principle
Doro/Audioline
AUB3MW, AUB6MW, AL505, Casino, Congress 100, 200, X50, Sim 200, Sensor 500, TEL15HS
Ericsson
Dialogue 4147, Dialogue 4186, MD110
ESI:
ESI-48-Key IP Feature Phone and 48-Key Digital Feature Phones
General Electric:
GE Telephone Model 2-9451, 2-9490
GrandStream IP Phones:
Budgetone 101,Budgetone 102
GXP280