Sennheiser / EPOS EXPAND SP 30+ Portable Bluetooth PC Speakerphone with BTD 800 | eBay
EPOS Headsets | Wireless Bluetooth Headsets | EPOS Sennheiser Adapt 660 AMC Wireless ANC Headset, With BTD 800 USB Adapter, USB-A (Black) (1001125)
Amazon.com: EPOS Enterprise BTD 800 USB | USB-A Bluetooth dongle|Connect Any EPOS Bluetooth Audio Devices Your PC/Mac with a Rapid Bluetooth Connection via This USB-A Dongle, Black : Electronics
Sennheiser BTD 800 USB Quick Guide | Manualzz
Sennheiser BTD 800 USB Network Adapter (504579): USB Network Adapters: Amazon.com.au
Epos / Sennheiser Adapt BTD 800 USB ML Dongle 1000227