Silencer Central Banish 12 Choke Tube Improved Modified Black. They thread directly into the suppressor providing a secure seamless fit. Made from 17-4 PH stainless steel with a Black Nitride finish theyre durable corrosion-resistant and lightweight just 0.3 ounces and 1 inch long adding minimal bulk to your setup. Specifications for Silencer Central Banish 12 Choke Tube: Manufacturer: Silencer Central Color: Black Finish: Black Nitride Fabric/Material: 17-4 PH Stainless Steel Gauge: 12 Length: 1 in Package Contents: Silencer Central Banish 12 Choke Tube Silencer Central 100000350021: Banish 12 Choke Tube Improved Modified Black