SEE COMPATIBLE PHONE LIST IN DESCRIPTION. 【NOT for Cell phones and Computers】Direct connect landline telephone headsets ONLY Compatible with Some Specific Phone Models from Polycom Mitel ...

2.5mm jack curly clable with Plx QD "Works with Ciso SPA Series and other Cordless phones with 2,5mm Standard Headset Port.(3 poles with 2 black bands), No Smart phone use. Works with Grandstream ...