I designed this magnet mounted reflector to fit my Godox V1 flash, but it may work well with other roundhead strobes. In the need of a portable flash reflector that also had a large enough profile to soften the flash, I designed this to be tall and wide but also reversible when not in use. The curved reflector provides a grab onto the strobe body while reversed to hold in place. Intended use is for hot shoe mounted flash with strobe pointed away from subject so reflector provides fill light to subject. About 2/3 of light is reflected towards subject, and the remainder third can provide bounce light from surroundings.

At the base there are eight holes for 3mm magnets to be inserted. I used 5 stacked 3x2mm magnets (40 small magnets), but if you have rods of that size that will work even better. I have printed this in only PLA type plastic, and I have not tested on other materials yet.

Designed in freeCAD, edited on PrusaSlicer