When there is no picatinny rail is available on the rifle, the front scope mount allows the use of Clip/on NVG and Thermal units by attaching to daytime rifle scopes. The attachment clips these devices onto the front of their scope.
#1C - for Daytime Optics with 42-50 mm Objective Diameter
#2C - for Daytime Optics with 51-59 mm Objective Diameter
#3C - for Daytime Optics with 60-65 mm Objective Diameter