It's the same cable as for my DMC-FZ200 and a whole wagonload of older and newer Panasonic models. Quite a number of third-party sources for cheap variants. It's definitely not compatible with any standard USB connector and may have been around before micro-USB was standardized. Also the socket contains pins for video I think. Here are photographs of socket (the right one in the photograph is USB/AV, the left being HDMI) and plug: So bite the bullet and get one. They are comparatively cheap and ubiquitous. Usually it's more convenient to just swap the SDcard though. With the FZ200, the corresponding flap is so close to the tripod mount that you cannot do so without unmounting the camera. The solution I finally adapted was using a lens clamp for holding the camera on the tripod. That way, the SDcard flap stays accessible. It may well be that the GM5 does not have a similarly absurd SDcard access position but I thought I'd mention it just in case.