Base screws are 6-48 X 1/4" long. Ring screws are 6-40 X 5/8" long. Both screws use 7/64 Allen wrench. Height of mounts from top of receiver to centerline of scope tube is medium 1.06". Mount fits right hand firearms. Long action - Outside to outside of rings is 4.820" Standard rings have 2 screws per ring and rings are .63" wide. Tactical rings have 4 screws per ring and are .80" wide. 4 Hole to hole spacing dimensions are .70", 3.931", .70".Features :Precision Machined from a Solid Block of Top-grade Billet 6061T6 AluminumNo Moving Parts Between the Firearm and the Scope67% Lighter than Comparable One-piece Mounts with Four Times the Threads and Precision Socket-head Cap Screws for Absolute Strength and SecurityAbsorbs Shock and Withstands Temperature Extremes Better than Steel Mounts at a Fraction of the Weight