The Crimson Trace CMR-201 Rail Master Universal Laser Sight is a compact, rail-mounted aiming device designed for firearms equipped with M1913 Picatinny or Weaver-style accessory rails, including many pistols, rifles, and shotguns. It features a 5 mW Class 3R red laser with a wavelength range of approximately 620–670 nm, producing a visible dot of about 0.5 inches at 50 feet, and is factory-sighted at that distance while allowing user adjustment for windage and elevation. The unit operates on a single 1/3N lithium battery and provides over four hours of continuous runtime. It includes multiple mounting inserts to support a wide range of firearm platforms and uses ambidextrous, instant-activation controls for quick operation. Designed for stability and ease of use, the laser sight mounts directly to accessory rails and delivers consistent aiming performance for training and general shooting applications.