This is the Du-Bro R/C Bolt-On Pressure Fitting.

Features

Brass pressure fitting.
Brass nut.
Fiber washer.
Easily mounts anywhere on the muffler by drilling a hole and
bolting it or taping a smaller hole.
Tapping instructions provided.

Includes

(1) Bolt-On Pressure Fitting

Requires

#36 Drill
#28 Drill