Start of lstUrls_of_images_in_html_description Product Number: JCOCN- These Optima Choke tubes are designed for 12 gauge shotguns using the Optima-Choke system specifically. They are longer and slimmer than conventional Mobilchoke tubes. Thanks to the elongated cone they minimize pellet deformation and improve shot patterns. Diameter & Sizes #JCOCN13 – Full – 0.694\