QD-L is designed for use on rifles with full length rails such as the FN SCAR and ARs with one-piece upper receivers.
QD-L places optical center 1.5 inches above the rail to accommodate most folding sights.
M10 QD-L mount fits 20mm rail
fits 1 inch, 30mm diameters
with 0, 20, and 30 MOA of inclination.