ETS-Lindgren 3184 Broadband Mini-Bicon Antenna - Manual (Page 20)

20 | Mounting Instructions
To direct mount, attach the mount to the 4-TR using the threaded insert on the
side of the mount. Rotate to tighten into place.
To use the extension, attach the extension to the mount using the threaded
insert on the side of the mount, and then turn the extension to tighten. Attach the
extension to the 4-TR using the threaded insert on the bottom of the extension.
Rotate to tighten into place.