Vortex product line Pro assembly rings.This is a base assembly, but it is well made and will do your job on a hunting rifle as well as many other assemblies available on the market at this price level.Series Pro rings combine reliability and strength with high quality machining to ensure maximum and consistent accuracy of firing. Primarily the assembly is designed for hunting rifles, but it will also serve other purposes in an emergency, such as sport shooting or tactical purposes. Circles are made of high quality aluminium with hard eloxing of the surface.They are efficient, light and durable, with four torx T-25 (star notch) bolts for secure attachment.The key to screw them is part of the van.The assembly is simple and snagging the rings is easy.This mounting is also available with less distance top of bar – axis of mounting (bar – center of rifle regard).