- Clear static-free reception- Electret transmitter provides extra-clear voice- Hearing aid compatible- Charcoal color- Works with all Cisco 78xx, 88xx and DX600 series phones- Not compatible with Cisco 79xx models. See Clarity WS-2620-24 Cisco Phone 7900 Push-To-Talk Handset instead- Not compatible with Cisco 6900, 8900, 9900, Use Clarity Walker WS-2800 Cisco Phone 6900 8900 9900 PTT Handset instead