One piece body Design for better scope alignment. Two integral 30mm rings with 1" size inserts(installed as shown in picture) Offset design to better work with scope eye relief Center height: 1.58" (40mm). Perfect for flat top AR15 Good for Magnified optics scopes with objective lens size up to 60mm Ring width: 0.62" Openning between rings: 2.16" Attaches to flat top rails, Picatinny or Weaver Locks firmly in place with 1/2" hex screws. Kit includes a flat clamping nut for easier and faster on and off Made of heavy duty quality aluminum alloy Anodized black matte finish Overall length: 3.43" Weight: 4.6OZ Base rail length: 2" Recoil lug: cross-slot steel bolt shaft