WHAT DOES OCK ISLAND 20 GAUGE SINGLE SHOT MEAN?

SKU 52780129 - RIA's Traditional single shot shotgun incorporates a vent rib, contoured barrel with muzzle brake. It utilizes a woodgrain polymer stock, silver anodized receiver and black barrel.Single Shot comes back to daily life using this 20" 12GA Rock Island Armory. Vented Rib barrel with barrel chromed inside, this shotgun cannot be conquer e