Rail mount, will accommodate Picatinny or Weaver standard red dots and optics. Keep your Holographic Scope Red dot and other optical accessories all in the same center line. Rail riser with See Through Design ,Single piece machined aluminum ,Sturdy and lightweight. Crafted from aircraft grade aluminum，matte black hard coat anodized. Picatinny Mount base with recoil stop.zero wiggle - guaranteed to hold zero against the toughest of recoil.(not suitable for weaver）