WIDI Master by CME is a virtual MIDI cable that allows Bluetooth devices to be connected to your MIDI instrument. Using WIDI Master with Wave allows you to connect Wave straight to your hardware device (synthesizer, guitar effect, etc. as long as it supports MIDI) without the need for a computer.
You need to configure Wave to work with your instrument using Wave's companion software, Softwave. Note that you need to download the newest version of Softwave for it to work.