Precision Reflex Build Your Own Rail Steel 18in Black. This Picatinny Rail from the experts at Precision Reflex is a 6061 extruded white aluminum/1913 rail that can be operator machined to the operator's design. The Precision Reflex Aluminum/Steel Build Your Own Rail Customizable is made from T6 6061 extruded white aluminum/1141 high strength steel with full 1913 rail. For a great way to make sure you have a stable surface on which to mount your favorite devices choose the Precision Reflex Aluminum/Steel Build Your Own Rail. Specifications for Precision Reflex Build Your Own Rail: Manufacturer: Precision Reflex Cant: 0 MOA Gun Make: AR Platform Width: 0.835 in Package Contents: Precision Reflex Build Your Own Rail Precision Reflex 02-BYO-18S: Build Your Own Rail Steel 18in Black