This is the Super Modular Rail MK4, M-LOK from Geissele. This rail is 15″ long and made to fit mil-spec upper receivers. This rail features M-LOK technology for the attachment of compatible accessories. The top of of the is 1913 picatinny rail with the end of the rail having short 1913 picatinny rail sections as well. The rail is made for low profile gas systems and may not work with other type gas systems including gas piston systems. Included is a Geissele low profile Super Gas Block.
Features and Specs: