The highly anticipated CMR-201 Rail Master Laser Sight is an instantly activated universal laser sight for Picatinny or Weaver rail equipped pistols and rifles. The CMR-201 marks Crimson Traces first universal fit laser sight and built with the industry leading quality, ergonomics, and fit. Fits pistol, rifles, and shotguns with M1913 Picatinny or Weaver-style Accessory Rail. Activation Location – Dual Side Activation. Activation Type – Instant Activation. Attachment – Accessory Rail Attachment.