Dead Air Blast Shroud w/ DA428 KeyMo Adapter (HUB 1 3/8-24) Includes DA428 KeyMo Adapter (HUB 1 3/8-24 compatible);Material: 4140 HT alloy steel;Finish: Black nitride;Length: 3.11 inches;Weight: 7.4 ounces;Through bore: .458 caliber;Reduces muzzle concussion and sound;Minimizes muzzle rise for better sight picture;Extends muzzle forward to reduce hand interference;Modular design compatible with other Dead Air accessories and suppressorstable.productattributes, .productattributes td { border-bottom: 1px solid #ddd; border-collapse: collapse; padding: 2px; text-align: left; } Item Category Code: 7600 Product Group Code: 7600P Inactive: No Prop65 Applies: Yes Prop65 Cancer Harm: Yes Prop65 Chemical: Lead