X 1/4" UNF, 5/16" UNF, 3/8" UNF, 7/16" UNF, 1/2" UNF, 5/8" UNF. x 5/16" UNF, 3/8" UNF, 7/16" UNF, 1/2" UNF, 9/16" UNF, 5/8" UNF, 3/4" UNF. Brass UNF Male to Female Thread Sump Plug Pipe Fitting Adapter.
eBay