This is an extruded solder spool holder for standard solder spools. The width between sides is 2-1/4" and the spindle diameter is 3/4". Nothing fancy going on here but it does sport three slots in the rear for pen-type flux or tools and it has two arms off the sides for rolls of solder wick.

Slightly hard to print as the corners tend to lift off the build platform. The "feet" can be sanded flat if needed.