Designed and built for the rigors of tactical shooting and massive recoil, Xtreme Tactical Rings are not out of place on varmint rifles or big game rifles that may be exposed to the abuses of hard hunting and magnum super-strong yet surprisingly lightweight, six-screw aluminum rings anchor scopes in place on any Picatinny rail or Weaver-style base to deliver unfailing return-to-zero. - 30mm (Pair)- Low (1/4")manufacturer no: 420160bar code: 000381201607manufacturer : Burrisshipping dimensions: weight: dimensional weight: (w) (h) (d).