Designed for use with all M-LOK compatible handguards and forends" M-LOK aluminum rail sections allow the attachment of various 1913 Picatinny spec rail-mounted accessories such as lights" vertical grips" etc. Designed for use with all M-LOK compatible handguards and forends" M-LOK aluminum rail sections allow the attachment of various 1913 Picatinny spec rail-mounted accessories such as lights" vertical grips" etc.