The Rob Roberts Raptor BIZ Crio Plus 20 Gauge Choke is crafted from durable 17-4 PH stainless steel providing exceptional strength and reliability. Designed specifically for optimal performance with bismuth shot shells this choke is a valuable addition to the Raptor Series. Years of development and innovation have gone into creating these choke tubes utilizing the most advanced technology available. Please note that this choke is designed for single-barrel placement only ensuring a tailored fit for your shotgun.