This is a cap to go over the USB end of a "RAVPower Portable Charger 3200mAh External Battery Pack Power Bank with Ultra bright flashlight." I like this charger, and have carried it in my pocket for over a year. From time to time, though, it will turn on "by itself" because nothing protects the switch on the end. It's mildly recessed, but not really enough. This cap protects the switch, and also keeps dust out of the USB ports, etc.
I printed this at "high quality"
This was designed in OpenSCAD (file included), about as simply as can be, thanks to the hollow cylinder code. It's three cylinders, one for the base, another for the body, and a third for the tiny ridge that helps the cap lock onto the seam between the main body and the end cap. There are a handful of variables/parameters at the start of the code that you can play around with if the fit isn't to your liking.