Drum Bung 64 x 5 American Buttress with ¾” Combination Thread

Drum Bung, Rieke, PPA-57-B5, 64×5 buttress thread with x 3/4″ BSP insert well (can be knocked out and fitted with 3/4″ solid bung or vented ¾” bung).
Typically has the word “Buttress” embossed on the top of the bung.