HELP with broken flange on drain plug in fish box

[biggarfish]

The slightly beveled flange has broken off from the threaded 1" plastic pipe which drains from my fish box on the stern starboard side (1988 Grady White Gulfstream 230). The word "Klein" is stamped on the underside of the beveled flange but I can't find anything on the internet. Any help or suggestions?

 

[seasick]

the key spec id the diameter of the threaded section. There are lots of options like

Amazon.com : marine thru hull fitting

Pick your diameter, length, barbed or threaded tail, material and profile of mushroom top.

 

[seasick]

Forgot to mention. Is this a livewell or a fish box. The diameter of the hole may be important if you have a standpipe that you insert to fill the box with water. If there is no standpipe or plug, the inside diameter of the hole is not critical.