Polycom Compatible Plantronics VoIP Noise Canceling HW251N Headset Bundle for SoundPoint&reg; Phones: IP 300, 335, 450, 501, 550, 560, 600, 650, 670 | VVX300, VVX310, VVX400, VVX410, VVX500, VVX600, VVX1500 | CX300, CX600, CX700 BUNDLE OF 2 ITEMS: Plantronics HW261N Headset and Ergonomic Polycom Telephone Interface Cable COMPATIBLE POLYCOM IP PHONES: IP335, 430, 450, 500, 501, 550, 560, 600, 601, 650, 670, CX300, CX600 CX700, VVX 300, VVX 310, VVX 400, VVX 410, VVX 500, VVX 600, VVX 1500 IMPROVED ERGONOMIC CONNECTORS: Allows for easy disconnect from phone without removing headset and reduce hand fatigue with contoured connectors. It is now easier to disconnect and reconnect cables. PLANTRONICS SOUND QUALITY: Ultra Noise-Canceling microphone filters out background sounds. Plug-n-Play easy of use with included cable. Premium Plantronics Wideband Audio for rich audio. GUARANTEE COMPATIBILITY: 100 Percent Happiness guarantee. If you have any compatibility questions or require support contact our friendly and factory-trained, Virginia-based support specialists. Unlike other big box sellers we love to provide pre sales and post sales support to our Amazon customers.