Sometimes, you discover a piece of kit and wonder, "Why has nobody done this before?" The in-built rechargeable battery removes the need for installing a separate battery - very clever. I fitted this pre-amp to a dulcimer, rather than the ukulele it is marketed for. I purchased a 40mm piezo pick-up to replace the one supplied with the unit, which would have been too long for the short saddle of a dulcimer. It works fine. The tuner display is small but clear, and pressing the tuner button automatically cuts the signal out to the PA. NOTE: unless you are a skilled woodworker, the fitting would be best left to a luthier. Excellent service from Thomann, as always in the past. I would thoroughly recommend this piece of kit.