Area 419 Arcalock 8 in Universal Flat Rail Black. They became very popular because they solved two important problems: they eliminated the need for friction lock systems that rely on a set of keys to lock the rail in place and they eliminated the need for rail expansion panels that add no additional weight to the rifle. This ARCALOCK rail fulfills both of these needs. The ARCALOCK system uses a mechanical lock much the same way as a t-nut or wing nut into an aluminum rail that can be installed by a variety of different methods. No more sliding rail under pressure or awkward installation. The ARCALOCK system utilizes a modular approach to add remove and install rails. You can be quite creative but you can count on the ARCALOCK system to provide solid performance. Add this to your arsenal today and see the difference. Specifications for Area 419 Arcalock 8 in Universal Flat Rail: Manufacturer: Area 419 Color: Black Fabric/Material: Aluminum Hand: Ambidextrous Gun Type: Rifle Gun Make: Universal Gun Model: Universal Length: 8 in Width: 1.5 in Height: 0.5 in Weight: 0.8 lb Condition: New Country of Origin: USA Package Contents: Area 419 Arcalock 8 in Universal Flat Rail Area 419 419-ALK-UNIV8RAIL: Arcalock 8 in Universal Flat Rail Black