Larue Tactical QD Cantilever Scope Mount - LT104 LaRue Tactical QD Cantilever Scope Mount - LT104 Mounting Surface - 4 Inches Centerline height (top of rail to center of optic) - 1 - 1.41, 30mm - 1.5, 34mm - 1.56 Inches Cantilever - 1.87 Inches Weight  6.9 ounces