A few versions of this hat were released and sold through merchandise forms in the late 70s. It appears to be the logo patch from the Love Gun merc form sewn onto a hat.

This hat has a mesh backing, the patch with an "R" below the logo, and a cord across the brim... likely from 1979/80.

Hat is listed as size X-XL. 

Near mint condition.

Images are of exact item.