Ever lost one of these before? I sure have! Now you can 3D print replacements!
I have included threading that allows the cap to screw on to form a snug and reliable fit. Tolerance is included to accommodate for the inherent inconsistencies of 3D printing.
UPDATE: 3/5/18
Thickness issue fixed where threading meets top
UPDATE: 6/19/18
Added second file with thickened walls for printers with larger nozzles.