Warranty: As customers of Cosyplus, you can always choose return for replacement or refund within 45 days. ONLY works for home office cordless phones with standard 2.5MM headset jack. Pls kindly check the port on side or bottom view of your phone. Compatible List(Part): DO NOT BUY THE ITEM IF YOU CAN’T FIND YOUR PHONE MODEL IN LISTS, CONTACT US FOR ADVICE. Panasonic: KX-NT136, KX-NT343, KX-NT346, KX-NT366 ,KX-T7603, KX-T7625, KX-T7630, KX-T7633, KX-T7636, KX-T7730, KX-T7735 and more AT&T: SL82418, SL82318, SL82118, SL80108, SB67158, SB67148, TL88002, TL86103, TL86003, TL76108, TL7610, TL88102, TL86109, TL86009, CL82550, CL82500, CL8230, CL82309, CL82350, CL80109, ML17928, ML17959, ML17939, ML17929, ML993 and more Uniden: TRU9465, TRU9385, TRU9380, TRU9360, TRU9496, TRU9488, TRU5885, TRU8860 TRU9466, TRU9460, TRU9480, TRU9485, TRU9565, TRU9585, DECT4096, DECT1060, DECT4086, DECT4066, DECT3080 DECT2085, DECT2080, DECT2060, DECT1080 Cisco Linksys: CIT200, CIT300, CIT310, CIT400 SPA921, SPA922, SPA941, SPA942, SPA962 Cisco SPA: 303, 501G, 502G, 504G, 508G, 509G, 525G 512G 514G,525G2 Cisco: 7985 Unified IP phones Polycom: IP320, IP321, IP330, IP331, SoundPoint Pro SE-220 SE-225 Grandstream:GXP-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) Gigaset: C610 IP, C620H, C430, S79H, S67H, CX610, C610, S850, C470, C455, C455, C450 Zultys Technologies: ZIP 4x4, ZIP 4x5 IP Phones Cosyplus Phone Headsets for Office Phones with Microphone, Wired Mono Telephone Headsets For Panasonic Cordless Phones with 2.5mm Jack Plus Other Home Office DECT Phones AT&T ML17929 RCA Vtech Cisco Polycom2.5MM TELEPHONE HEADSET: This Phone Headset is compatible with Panasonic Cordless phones AT&T ML17929 VTech CM18445 RCA 25424RE1 Uniden Cisco SPA Grandstream Polycom Clarity XLC3.4 Yealink W52P Zultys Siemens Gigaset Cortelco Office IP, most Cordless Dect Phones and some old cell phones with standard 2.5MM HEADSET JACK. SEE MORE COMPATIBLE PHONE LIST IN DESCRIPTION. 2.5MM TELEPHONE HEADSET: This Phone Headset is compatible with Panasonic Cordless phones AT&T ML17929 VTech CM18445 RCA 25424RE1 Uniden Cisco SPA Grandstream Polycom Clarity XLC3.4 Yealink W52P Zultys Siemens Gigaset Cortelco Office IP, most Cordless Dect Phones and some old cell phones with standard 2.5MM HEADSET JACK. SEE MORE COMPATIBLE PHONE LIST IN DESCRIPTION.