This is a Magpul Industries known as the Rail Light Mount, model MAG498-RT-BLK.
The Rail Light Mount fits on any standard 1913 Picatinny Rail" is available in Right or Left side models" and integrates with the Magpul XTM panels. It positions the weapon light high and cantilevered forward" at the 11 o'clock or 1 o'clock position" to allow a more forward support hand position" keep the light tucked in close to the bore" and to minimize barrel shadow. A textured thumb ramp is integrated to provide the user an index point" aiding consistent hand placement and light activation. Constructed of reinforced polymer" the Rail Light Mount nearly eliminates light compatibility concerns by conveniently including everything you need to mount Surefire 300 and 600 series Scout Lights" 1913 Picatinny attachment pistol lights" and all light bodies from 0.75" to 1.03" in diameter via the included set of anodized aluminum mounting rings. Models are available to position the light high at 11 o'clock (LT" Left side model) or one o'clock (RT" Right side model). Made in U.S.A.
Features:
Fits on any standard 1913 Picatinny Rail
Positions the weapon light high and cantilevered forward
Textured thumb ramp
Forward support hand position
