Plantronics S11 is a complete system including amplifier base and headset as well as all necessary cords to connect to most single- and multi-line corded telephones. Over-the-head headband style headset. Amplifier base allows you to separately control incoming and outgoing volume; also offers mute control, noise-canceling microphone, in-use indicator light on base, A/C power plug (no batteries needed) and convenient headset stand. Please note that the S11 does NOT have QuickDisconnect feature. If you need QuickDisconnect, please click here for commercial-grade products
. Covered by 1-year factory warranty.