ONLY compatible with below telephones,Pls make sure check it before you order it.
Avaya 1608,1616,9601,9608,9611,9611G,9620,9621,9630,9631,9640,9641,9650,9670,J139, J169 and J179 Phones
Cisco 7902,7905,7905G,7906G,7910,7910 7911,7912 IP Phones
Cortelco Fanvil C58, C58P C62, C66
Panasonic KX-T Series phones such as: KX-T2260,KX-T2310,KX-T2315,KX-T2365,KX-T2368,KX-T7220,KX-T7230,KX-T7330,KX-T7433,KX-T7625,KX-T7630,KX-T7633,KX-T7636,KX-T7665,KX-T7720,KX-T7730,KX-T7740 and KX-T7750
Yealink T20P,T22P,T26P,T28P,T32G,T41P,T38G,T42G,T46G,T48G all Series.
Grandstream GXP-1200,GXP-14XX,GXP-2010,GXP-2020,GXP-2100,GXP-2110,GXP-2120,GXP-2130,GXP-2140,GXP-2160,GXP-280,GXP-285,GXV-3240,GXV-3275