Carlson's Buckshot Ported Choke Tubes for Winchester 12 Gauge are engineered for precision and performance. Delivering tight consistent patterns with 00 and 000 buckshot it features a ported design to effectively reduce recoil and muzzle jump. Made from durable 17-4 heat treated stainless steel it is compatible with lead steel and hevi-shot loads though not to be used with steel shot larger than BB or exceeding 1550 fps. This extended black-finished choke is designed for Invector configurations and extends approximately 1" from your barrel. Perfect for hunters and shooting enthusiasts the .700 constriction optimizes performance for both small and large loads.