Wireless desktop headset system. Connection to the device: EHS adapter, RJ-9. Wearing style: In-ear, Convertible/Ear hook/Overhead, Wearing mode: Mono. Suitable for office use. Microsoft certification: No. Range of up to 100 m. Usable as an ear hook and headband model. Includes EHS cable APS-11. The wireless headset CS540 from Plantronics' CS family provides greater freedom of movement in the office and enables effective multitasking, as your hands remain free. Tasks can be completed flexibly and up to 100 m away from the desk. Call control is managed via a multifunction button (answer/end call) and a volume button (with mute). The included EHS cable APS-11 allows for call control of landline phones. Calls can be made entirely without the HL10 handset lifter using this cable.