The lightweight, streamlined design of the Daniel Defense Rail-Mount Fixed Front Sight makes it unobtrusive and snag-free. The one piece design makes it easy to install on any MIL-STD-1913 rail and it secures with a slotted fastener threaded into a self-locking stainless steel thread insert. Special attention was paid to facilitate the use of compact weapon-lights forward of the sight, such as the X300, TLR-1, etc. The concave radius on either side of the sight is a great place to rest your thumb for easy, ambidextrous activation of the light..