The Samson Manufacturing Evolution Series free float rails are customizable LR-308 handguards. The Evo rail attaches to a proprietary barrel nut (included). Two locking tabs ensure the rail does not rotate under stress. The continuous top rail allows you to mount optics anywhere along the top of the rifle and allows same-plane iron sights to be mounted. The top rail has also been relieved to accept most aftermarket piston conversion systems. Each Evo handguard includes two 2", and one 4" customizable rail sections that can be mounted anywhere along the handguard tube. The interior of the tube is 1.56" in diameter, allowing most suppressors to fit underneath. The EVO Extended Rail series feature a front sight cut out, so the lower portion of the handguard extends out past the sides of the front sight post, giving you more mounting options on guns with shorter gas systems. The EX handguards are the perfect choice for gas piston conversions. Notes:Current shipments of th...