HIVIZ has something for every shotgun, including shotguns without ribs. this simple snap-on sight offers the LitePipe interchangeability that HIVIZ is known for in a strong, easy-to-attach design for any plain-barrel gun. Offered with two different diameter green and red LitePipes. Fits all 12, 16, and 20 gauge plain barrel shotguns. Fiber Diameter: 0.135"/0.175".