The ProTac Rail Mount HL-X is a 1,000 lumen weapon-mounted light featuring a dedicated fixed-mount for Picatinny rails. It uses either a remote switch or a standard push-button tail switch, and can run on multiple battery sources.

Other Features:

Dual fuel - uses two CR123A lithium batteries (included); also accepts one Streamlight SL-B26™ protected Li-Ion USB rechargeable battery pack
Easy to use pressure switch comes with a button for on/off and a pressure switch for momentary activation.
Integrated rail clamp attaches to MIL-STD-1913 rails
Easy to attach, secure mounting
Durable, anodized aluminum construction with impact-resistant tempered glass lens
IPX7 rated with the Standard button switch installed; waterproof to 1 meter for 30 minutes.
IPX4 rated with the Remote Pressure Switch installed
Operating temperature: -40°F to +120°F
Anti-roll head
Includes two CR123A lithium batteries, remote pressure switch, push-button tail switch, remote retaining clips, double-sided tape and zip ties
Solid State power regulation provides maximum light output throughout battery life