Fast, No-Tool Knob For Harris Bipod
Install or remove your Harris Bipod in just seconds by adding this
easy-to-turn thumb knob. Mounts in place of the Harris
mounting/attachment screw. Can also be used with the Harris
#6A Adapter for faster bipod setting on a forend rail.
Big Book Catalog, Issue:66, Page:370
SPECS: Steel, blue. .750" (19.2mm) diameter knob.