This single headset has 2 kinds of plug, the RJ9 crystal plug and 2.5mm plug, so please leave a message which plug you need after your order,,otherwise I will default send the 2.5mm plug.

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

Headset Key Features::

The microphone (Mic) is noise-proof and can screen 90% background noise so as to perfectly and truly present the sweet voice of the telephone operator.
The flat speaking tube shows the unique design and high quality even more and can rotates by 300 degrees.
Head clip can stretch freely so that you can wear it comfortably.
The voice communication effect is super clear.
Plug: 2.5mm (RJ9 plug is also optional)
TWO-year free warranty is guaranteed.

Other Features:

1. Stylish goose neck design, providing clear communications

2. Acoustic Shock Protection circuit
3. Lightweight, durable and comfortable for all day use
4. Hearing on one side and can be worn on either ear
5. Adjustable headband
6. Replaceable soft foam or soft leatherette ear pad.

7.Additional 1 pc ear pad is provided.