The Corvus Defensio Aimpoint M4/PRO Base Mount was especially developed to the demands of the Austrian Police. The demands were: fixed assembling (no lever), a center line of sight of 1.54 inch over the upper surface of the MOI Picatinny Rail (same rail height as standard A3 Steyr receiver rail) and no presence of sharp or prominent edges to not insure the support hand when using the original A3 charging handle. The mount fits all Aimpoint M4 and PRO models.
Note: When used with an Aimpoint PRO the original Aimpoint PRO interface ring mount must be used as well! This ring mount is not included with the CorDef Aimpoint M4/PRO Base Mount!