A USP (Undersaddle_Piezo) pickup system for stringed instruments. With integrated microphone in the endpin preamplifier and rechargeable battery. The pickup system is the interface between instrument and amplifier. The special features of Lily one are the design, as the system reliably monitors the charge status of the battery and gives a visual warning in good time before the battery is running low. This is done via LED on the sound hole control panel. The system is charged with the included USB jack cable connected to the endpin jack socket of the guitar. For this purpose, a standard 5V, a power bank or a PC with USB charging output is sufficient.