The Aimpoint® FlipMount is a quick attach/detach mount that can be quickly flipped in or out of the optical axis. The FlipMount is designed primarily for use with Aimpoint magnifiers. Can also be used to mount other optical equipment with a 39mm tube. The FlipMount with TwistMount™ base is offered in two different heights to accommodate various sight mounts. Total height (art.nr 200251): 47.5 mm (1.9in) - for AR15/M4 Carbine. Length: 40 mm (1.6in). Width: 54.5 mm (2.1in). Weight (art.nr 200251): 129 grams (4.6 oz). Not recommended for use with 6X magnifiers