The Vortex Picatinny-style ring(1) features a wide six-screw design for additional surface area to keep your optic true under the even the hardest hitting recoil of today's rifles. When purchased as a single ring, they are ideal for mounting 30mm tube red dots or magnifiers, and are available in a variety of heights for a custom fit and feel. When 1 pair of rings are purchased, these Picatinny style rings are a perfect mounting solution for rifle scopes on an AR-15 platform. Ring Height:(measured from base of ring to center of scope tube)Low:0.83"Medium:0.97"High:1.18"Extra-High(Absolute Co-Witness) : 1.46"Extra-High ( Lower 1/3 Co-Witness): 1.57" Notes Sold as 1 Individual Ring or 1 Pair of 2 RingsFits standard 1913 Picatinny-style railsMounting hardware includedLimited Lifetime Warranty