Vtech VSP505 ErisTerminal DECT Cordless Headset VoIP Phone and Device Range: up to 500 feet from the base Mute, flash and volume controls, DECT 6.0 technology and a noise-canceling microphone deliver interference-free conversations. Accessory headset only; requires a VSP725 Desk set or VSP735 Desk set to operate. Multiple wearing styles, magnetic charging cradle.