Voistek Corded Binaural Call Center Telephone Headset Noise Cancelling Headphone with Flexible Microphone for Cisco Linksys Polycom Panasonic Office Deskphone DECT Cordless and Cell Phones with 2.5mm Headset Jack (H20D25MM) DO NOT BUY THIS ITEM IF YOU DON'T HAVE ONE OF THE PHONE MODEL LISTED BELOW IN DESCRIPTION. CONTACT US FOR COMPATIBILITY GUIDE IF NEEDED. This 2.5mm Telephone Headset Connects directly to a 2.5mm headset jack on most basic and business phones such as Polycom Cisco Linksys SPA, Panasonic Zultys AT&T Aastra GrandStream and many many cordless DECT phones or Cell Phones with standard 2.5mm Headset Port. Only compatible with phones with 2.5mm standard headset jack. For cell phone with 3.5mm headset jack like iPhone Samsung LG HTC Blackberry Huawei ZTE...etc, pls kindly check our items: VOISTEK K10J35 or VOISTEK H20J35 Superior Call Center quality Cordless phone headset, excellent sound quality, lightweight, durable and comfortable for all day use Noise canceling microphone to reduce background noise and Acoustic Shock Protection circuit to protect your hearing.