Rail interface system or rail integration system (RIS for short, sometimes also referred to as rail accessory system, RAS) is a generic term for a standardized rail system for attaching accessories to small firearms such as pistols, rifles and light machine guns. Such accessories commonly include tactical lights, laser aiming modules, forward hand grips for improving weapon handling, telescopic sights for long-range targets, and reflex sights/red-dot sights for short/medium-ranged targets, back-up iron sight, bipods/tripods, and bayonets.