Sylvan Arms Conversion Block Features The Sylvan Arms Conversion Block installs directly into a Mil-Spec AR-15 lower receiver allowing it to accept popular Sig Sauer P320 9mm magazines without requiring a dedicated PCC lower. Built from a combination of steel and 6061-T6 aluminum the block is engineered to hold up to repeated magazine insertions and removals without excess wear. The black anodized finish resists corrosion and matches most factory-finished AR-15 builds for a clean uniform appearance. A 9mm-specific upper receiver is required alongside this block for proper functionality and it does not include last-round bolt hold-open capability. Installation is a simple quick swap-out process meaning shooters can convert an existing 5.56 lower into a 9mm-compatible platform without permanent modification. At just 4.2 oz the block adds negligible weight to the completed build while unlocking compatibility with widely available and affordable P320 magazines. Sylvan Arms backs the Conversion Block with a limited lifetime warranty and a 100% satisfaction guarantee giving buyers confidence in the purchase. For AR-15 owners who want a cost-effective way to build a 9mm pistol-caliber carbine around Sig P320 magazines this conversion block is a smart practical upgrade. Sylvan Arms Conversion Block for Sig P320 Specifications Brand: Sylvan Arms Model: Conversion Block Compatible Hosts: AR-15 Sig Sauer P320 Magazines Color: Black Material: Steel and 6061-T6 Aluminum Finish: Black Anodized Weight: 4.2 oz Available At: GrabAGun