WA31 wireless audio receiver board is a small board with 2pin power connector and 3 pin analog output connect. You can easily install it into your old speaker WiFi/AirPlay enabled to play music wirelessly. It has other excellent features as below. - play music by WiFi without distance limitation - support AirPlay, DLNA, Spotify connect and Qplay streaming protocols - support playback lossless audio formats, FLAC, APE, WAV - support sample rate up to 24bit/192kHz - support multiroom streaming and control all room music by one app - play music from PC,phone,tablet, NAS and cloud It is a cost-effective and easy solution for DIY users to upgrade their old stereo audio system to wireless smart multiroom audio system, another application market is speaker integration for speaker manufacturer. Business inquiry: sales@rakoit.com Support: info@rakoit.com