Magnetic sight utilizes the Magni-Optic technology for vent ribbed shot guns.
MGH2007-I, Magnetic base sight to fit ribs from .230" to .330" (15/64 - 21/64; 5.8mm - 8.3mm).
MGH2007-II, Magnetic base sight to fit ribs from .355" to .440" (23/64 - 7/16; 9mm - 11.1mm).
Each package includes two bases with one set of magnets, two red pipes, two green pipes, and carrying case.