Male 2.5mm to Male RJ45 Cord for Sennheiser and Plantronics
Amazon.com: Telephone Headset w/ 2.5mm Jack Quick Disconnect Cord for Cisco Deskphone Plantronics Avaya Siemens Cordless DECT Phone for Call Center Office Work from Home w/ 3.5mm Audio Jack for Cell Phone
Poly Quick Disconnect 10' Cable to 2.5mm 70765-01 B&H Photo Video
Deluxe 2.5mm headset. Best Phone headset + 2.5 mm to plantronics QD cord, Monaural corded headset
Amazon.com: INNOTALK 2.5 mm Quick Disconnect Headset Compatible with Plantronics QD with Super Sound Monaural Noise Cancel Mic : Electronics
Plantronics MX250 Headset for Cellular Phones with 2.5mm Jack