Mounting Hardware is Included

This mount fits:
Ruger Blackhawk
Ruger Redhawk
GP100 (with adjustable rear sights)
GP100 Match Champion

This mount does not fit:
Ruger Flattop Revolvers

This rail mounts using the hole from your rear sight, but also requires you to drill and tap two additional holes in your reciever if your gun is not already drilled and tapped.

Rail Type: One Piece Picatinny
Machined from: Domestic 6061 T6 Extruded Aluminum
Finish: Matte Silver Anodizing
Overall Length: 4.3"
Height: .4" (Top of Receiver to Top of Picatinny)
Weight: 2 oz.
Quick Disconnect Ring Compatible: No
Ambidextrous: Yes
Torque Specs: 20 in/lbs
Mounting Hardware: #8-40 X 3/8 SHCS & 6-48 X 9/16 SHC Screws and T-10 Bit Included