The 2.5mm plug is used for following IP Phones and other telephone with 2.5mm socket.This list is not all inclusive.

For C i s c o SPA 501G， 502G， 504G， 508G， 509G， 525G
For C i s c o Linksys SPA921， SPA922， SPA941， SPA942， SPA962 models
For P o l y c o m 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 a n a s o n i c 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 G i g a s e t C610 IP， C620H

Item Condition: 95%Brand-new without retail package due to some slight scratching during the transportations.(Original item ，not a copy or clone)

P a n a sonic’s KX-TCA93 keeps your hands unencumbered for other tasks. Whether you need both hands for note taking (written or typing)， cooking， taking care of children， etc this set does the job. Ear hook is reversible for use on either ear， and the microphone is adjustable. Headset is compatible with select models of Pan as onic phones.

Item Features

Compatible with: KX-TG4500B， KX-TG9321T， KX-TG9322T， KX-TG6572C， KX-TG6572R， KX-TG4012N， KX-TG4013N， KX-TG4031B， KX-TG4032B， KX-TG4033B， KX-TG4034B， KX-TG4053B， KX-TG6511B， KX-TG6512B， KX-TG6513B， KX-TG6531B， KX-TG6532B， KX-TG6533B， KX-TG6534B， KX-TG6541B， KX-TG6542B， KX-TG6544B， KX-TG6545B， KX-TG7531B， KX-TG7532B， KX-TG7533B， and KX-TG7534B phones

Reversible earhook
Adjustable microphone
Mute function
In-cord Volume Control
Cord length: 4-feet
Connection: 2.5mm