Anyone happen to recognise this? It charges via usb, with the progress of the charge shown on a little white display, 0 to 100%. The are no buttons on it, just a battery visible, and two pins poking out of the pcb, though the pcb seems to suggest, it originally had four pins. There are two components, identified on the pcb, as 'mic1' and 'mic2', with a series of three holes, on the plastic case, opposite end to the pcb
