CS540: How to Adjust the Volume | Poly, formerly Plantronics & Polycom
Plantronics CS540 (C054) Wireless Headset Setup Guide- WITH Headset Port - YouTube
Plantronics CS540 EHS Wireless headset
Polycom Compatible Plantronics VoIP Wireless Headset Bundle with Electronic Remote Answerer (EHS) included | SoundPoint® Phones: IP 335, IP 430, IP 450, IP 550, IP 560, IP 650, IP 670, VVX300, VVX500, VVX310, VVX600, VVX400, VVX1500, VVX410
Plantronics CS540 Setup, Installation, and Users Guide
Plantronics CS540-XD Wireless Headset | 88283-01 - Headsets Direct