The X-15 Skeletonized not only adds a dimension of look, it is also lightens the magazine, allows the shooter to maintain an active round count, as well as improves function in high dirt environments. It is designed and built of the highest grade materials to give it unparalleled function, and rigidity. Engineered using our proven coil magazine technology, which allows side by side staging of ammo in a single stack. The streamlined design allows for no separation of ammunition during function, preventing malfunctions and lending to it s compact design. Its pending tension relief device allows the X-15 to operate nearly unlimited spring loads, allowing it to operate in weapons with capabilities 1100 rounds per minute. User friendly ergonomics and the ability to use your sling makes this the choice magazine for 3 gun competitors. Coated in Cerakote for friction reduction and proven reliability without using lubrication.. Manufactured in the USA, fits most M16/AR-15 rifles with improved M4 feed ramps.