Steven Lobel
Supporter
Graziano drain plug is 14mm hex head. Not a common size. Sold at Harbor Freight as part of 1/2" drive allen head socket set.
https://www.harborfreight.com/9-piece-38-and-12-drive-metric-hex-bit-socket-set-67880.html
https://www.harborfreight.com/9-piece-38-and-12-drive-metric-hex-bit-socket-set-67880.html