Bluetooth Audio Transmitter Board, Bluetooth 4.1 Stereo Sound Module Audio Transmitter Stereo Module Wireless Speaker Headphones : Amazon.co.uk: Business, Industry & Science
Discontinued] UCTRONICS Bluetooth 5.0 Mini Audio Receiver Board, Portable Wireless HiFi Stereo Music Transmitter for Headphone, Car Amplifier, Home Sound System, DIY Speaker