The Rob Roberts TSS Raptor Invector 20 Gauge Choke is designed for superior performance in wing shooting when used with premium tungsten shot. Part of the RRaptor Series this choke is crafted from high-grade 17-4 PH stainless steel ensuring durability and reliability. Years of development and advanced technology have gone into creating these choke tubes making them a top choice for shooters seeking precision and consistency. Note that this choke is designed for use in only one barrel of a shotgun.