Sennheiser BTD 500 USB Wireless Bluetooth Wi-Fi for Audio. | eBay
Amazon.com: BTD 500 USB Dongle : Electronics
Amazon.com: Kinivo USB Bluetooth Adapter for PC BTD500 (BT 5.1, Wireless Dongle Receiver for Windows 11/10/8.1/8/7, Raspberry Pi, Linux) - Compatible with Laptops, Headsets, Speaker, Mouse, Keyboard, Printers : Electronics