Leupold Mark AR mounting system features an aluminum 1-piece integrated base and rings. It is designed to fit a Picatinny rail and any scope with a 30mm maintube.

Leupold 177094 Integral Mounting System Mark AR Matte Black Aluminum AR-Platform Rifle 30mm Tube

Tube Diameter: 30mm
Model: Integral Mounting System
Color: Matte Black
Material: Aluminum
Firearm Type: Rifle
Rings Included: Yes
Firearm Fit: AR-Platform
Length: 5.43"
Includes: Mounting Hardware
Weight: 5.80 oz