Comdio H403VPA Corded 2.5mm (2 rings) Headset with Flexible Noise Canceling Mic + Volume Mute Control for Polycom Cisco Linksys SPA Office IP Telephone and Cordless Dect Phones with 2.5mm Headset Jack ONLY WORKS FOR SOME SPECIFIC PHONES. SEE COMPATIBLE PHONE LIST IN DESCRIPTION, BUY THE ITEM TODAY IF YOU HAVE ONE OF THE PHONE MODELS LISTED BELOW. Superior quality sound with the flexible adjustable noise cancellation microphone. Super Lightweight, Super Durable Headset with Comfortable ear and mic cushions. Direct connect over the head headset, No additional amplifiers or adapters required, Most easy setup headset solution. Professional Mic Mute / Volume Control built in.