JMac Customs Bravo Extended Blast Shield Muzzle Device 1.375-24 Thread Black. The adapter is designed to give 3/8'' cheek rise and is extremely lightweight made of 7075 T6 Aluminum Alloy and Hard Anodized This adapter will also allow you to install AR stocks that are designed for the ''fixed stock'' buffer tube. The adapter also has 2 QD sling points Only weighs 2.43 oz Does NOT have locking capability while folded. Specifications for JMac Customs Bravo Extended Blast Shield Muzzle Device: Manufacturer: JMac Customs Weight: 3.9 oz Condition: New Color: Black Fabric/Material: 17-4PH Stainless Steel Features of JMac Customs Bravo Extended Blast Shield Muzzle Device These will install in about 1 minute on the following 5.5mm folding rear trunnion rifles: Arsenal - SGL rifles Kalashnikov USA - KP9 KR9 Mod-2 requires a buffer tube castle nut & lock plate. Package Contents: JMac Customs Bravo Extended Blast Shield Muzzle Device JMac Customs BDS-37-EXT: Bravo Extended Blast Shield Muzzle Device 1.375-24 Thread Black