MMC makes the most rugged, fully adjustable, Ghostring rear sight for shotguns in the world today. Simply put, they are the best. The contoured base has integral protective ears of fully machined and hardened steel. It is held to the receiver by two oversized No. 8 screws. The ghostring aperture is capable of 30 MOA adjustment in both windage and elevation in positive 3 MOA clicks. These adjustments are quickly and easily made with a coin or the rim of a shotshell, requiring no special tools in the field. The elevation mechanism operates on an eccentric that cannot be over tightened or unscrewed. Ghostrings are available in standard Black Oxide finish, premium Teflon-coated or Nickel plated/Teflon coated finishes. The MMC Ghostring Shotgun Sight is compatible with the winged front sights on the Benelli M1S90, the Remington Slug Barrel, the Mossberg ramped front for ghost ring, Scattergun Technologies front sight, or most other ramped front sights that are at least 0.70" above the bore. Almost all models of 12 gauge pump and semi-auto shotguns can be upgraded with the MMC Ghostring Shotgun Sight to give you a state-of-the-art tactical shotgun sight. When ordering, provide the make and model of your shotgun.