The 
NUPROL NX200 Pistol Torch is a compact, 200-lumen tactical flashlight designed primarily for Airsoft pistols and rifles with a 20mm Picatinny RIS/Weaver rail system. It features an ambidextrous "rocker" switch for both momentary and constant-on activation and is constructed from alloy. 
Key Features and Specifications
Brightness: Features a genuine 200 lumen CREE LED bulb, suitable for illuminating dark CQB environments.
Compatibility: Designed to fit any standard 20mm RIS/Picatinny rail, making it versatile for both airsoft pistols and short barreled rifles/SMGs. A spare fitting plate and Allen key are included to ensure a secure fit.
Controls: The rear features an ambidextrous textured toggle switch that allows activation by both left and right-handed users. The switch can be pressed for momentary light or twisted for constant-on.
Construction: The body and head are made from a durable alloy, with a solid polymer toggle switch at the rear.
Power: Requires two CR123A batteries to function (batteries are not included).
Dimensions: The approximate product length is 9cm, height 3.4cm, and width 3.6cm.
Usability: Reviewers on Patrol Base UK mention it is highly intuitive to use and an excellent addition for low-light gameplay.