USB-C TO RJ9 ADAPTER: Connect an RJ9 landline office phone handset or headset to a USB-C laptop, desktop, or mobile device for seamless calls and video conferences; Extend the lifespan of existing landline hardware with this USB to RJ9 adapter COMPATIBILITY: Plug-and-play with Windows, macOS, Android, iOS, and iPadOS; Works with Sennheiser/EPOS UI760 Headset Amplifier and Plantronics/Poly Vista M22 Phone Amplifier; See gallery for RJ9 pinout details HIGH-DEFINITION AUDIO QUALITY: Equipped with a 32bit and 8 to 96kHz audio processor, this adapter delivers clear mono audio providing reliable call quality for VoIP applications COMFORT & FLEXIBILITY: The 6ft (1.8m) long cable offers flexible routing for a tidy setup while allowing freedom of movement during calls or when using videoconferencing applications; Ideal for office, remote work, or call center environments THE IT PRO'S CHOICE: Designed and built for IT Professionals, this USB-C to RJ9 jack audio dongle is backed for two years, including free lifetime 24/5 multi-lingual technical assistance