The Carlsons Bismuth Bone Buster Mid-Range Choke Tube for 12 Gauge is engineered to deliver unmatched performance with bismuth ammunition. Crafted from 17-4 heat-treated stainless steel using CNC precision machining it features an extended parallel section for tighter and more consistent patterns compared to standard factory choke tubes. This choke tube has undergone extensive testing with various loads ensuring devastatingly dense and reliable patterns every time. Compatible with lead Hevi-Shot and steel shot it offers exceptional versatility for hunters and shooters alike. Designed for Invector-Plus configurations with a constriction diameter of .025 this durable and efficient choke tube is the perfect choice for achieving precision and power in your shots.