Game Reaper 2 Signature Series two piece scope mounts fit long and short actions some super short actions left and right hand guns. Features machined from a solid block of top-grade billet 6061 T6 aluminum internal ring and base design allows for extra eye relief adjustment reduces scope damage from tightening rings no moving parts between the firearm and the scope up to four times the threads of other mounts for absolute strength and security and absorbs shock and withstands temperature extremes better than steel mounts at a fraction of the weight. Fits all action lengths. Both mounts are not the same part. Back mount is taller than front mount because receiver is lower on back end. Base screws are 6-48 X 1/4 long. Ring screws are 6-40 X 5/8 long. Both use a 7/64 Allen wrench. This Tactical model has 4 screws per ring.