UTG® Super Slim RDM20 Dovetail Mount, 0.33" Saddle Height, Precision Machined from 6061-T6 Aluminum and Finished in a Matte Black Anodization, 9mm - 11mm Flat or Round Dovetail Compatible, Optional Recoil Stop Pin Provides Additional Retention Against Bidirectional Recoil, Utilizes the Docter® Footprint