Salmon River Solutions SRS M-LOK Forennd Weight Black. These have M LOK bosses on the backside for a snug lockup on your stock or chassis. Mounting holes are offset for chassis with integral arca rails. Each set comes with 4 m lok fasteners and two weights. Each weight plus fasteners is 6 oz and a set is 12 oz. Specifications for Salmon River Solutions SRS M-LOK Forennd Weight: Manufacturer: Salmon River Solutions Color: Black Fabric/Material: 7075 Aluminum Features of Salmon River Solutions SRS M-LOK Forennd Weight Offset Arca Clearance M Lok Attachment Package Contents: Salmon River Solutions SRS M-LOK Forennd Weight 4 M Lok Fastener Sets Salmon River Solutions 1140: SRS M-LOK Forennd Weight Black