k-1A Rail systems on firearms are straight mounting brackets (usually made of strips of metal or polymer) on the gun's receiver, handguard or fore-end stock to allow sliding/variable-position attachment of optical sights and accessories such as tactical lights, laser sights, vertical/angled foregrips and bipods. Amongst many other accessories like sling attachment points. Which may be ether ring, loop and/or quick detach mounts using push button style hardware. To name just a few of the many options. An advantage with the multiple rail slots is the moveable positions to adjust for optimal placement of each item for each different user. Along with the ability to switch different items at different placements due to varying eye reliefs on gun sights, scopes & optics. Tactical usage and Shooting sports have both benefited from the extra options provided.