The E-Volv 2.2" Picatinny Rail by Mission First Tactical is a Military Standard 1913 attachment that delivers perfect alignment and is made to mount to either standard or Glacier Guard handguards. The rail is easy to install by using the existing vent openings. The E-Volv Picatinny Rail is designed to ensure that the mounting is parallel to the bore/barrel for proper ballistic alignment. Constructed out of heavy-duty polyamide from DuPont's Military Plastic Division. Made in the USA. Lifetime warranty. Dimensions: .752"W x 2.216"L x .574"H. Weight: 32 oz.