The WL-T Wireless Transmitter is compatible with WL-series wireless systems and the Katana-Air wireless guitar amp, providing a spare to use if your original transmitter is lost or damaged. When pre-charged, it also functions as a backup transmitter for live performances. To charge the WL-T’s built-in battery and establish a connection to your BOSS wireless receiver, simply follow the same procedures used with the original transmitter included with your system.