Traditional style bronze screw-in type transom drain plug.  The base has a 2" diameter, with a 1/2" screw-in drain.  This is the plug we use in the transom of our Peeler Skiff. 

To insure that water does not penetrate the transom, we suggest the drill-fill-drill method.

Attachment screws and silicone sealant not included, reguires (3) #10 x 1" Oval Head SB Wood Screws