American Defense Holosun 509T Lower 1/3 QD Mount

The American Defense AD-509T lower-one-third mount gives a Holosun 509T a taller mounting position than the co-witness version. It retains the same dedicated 509T footprint while adding quick-release attachment at the rail. The mount is finished in black anodizing for a clean match with common black optic setups.

Lower-one-third height changes where the sight sits above the rail without changing the optic itself. That makes this version useful when the preferred sight line is higher than an absolute co-witness arrangement but not as low as the low-profile model. The QD base lets the 509T remain attached to its mount if the assembly is removed.

This is the middle-height choice in the three AD-509T versions in this group. It is well suited to a build where the 509T footprint and lower-one-third position are already part of the desired layout. Compare additional dedicated optic mounts under optics and rangefinders.

• Fits Holosun 509T footprint
• Lower 1/3 optic height
• Quick-release rail connection
• Black anodized finish