New for 2016. This is the last flip cap you will ever need! Virtually indestructible, this cap will fit snugly on nearly all Vortex Optics and features a snap flat spring that will keep your line of sight unobstructed. Rifle ranges the world over are littered with broken flip caps. This is one cap you will most likely never see in a flip cap boneyard. The E-10 cap has three stop positions.