AD-509T Holosun 509T QR Lower 1/3 Mount

The AD-509T QD mount from American Defense Mfg is engineered for the Holosun 509T red dot and for use on pistol and carbine platforms that benefit from a compact, lightweight optic mounting solution. It is a one-piece unit precision machined to provide secure, repeatable attachment while minimizing added height. The mount includes the Patented QD Auto Lock Lever system to accommodate both in-spec and out-of-spec rail systems. Its lower 1/3 profile positions the optic for a reduced sight picture on many handgun and short-barrel configurations.

Key Specifications

• The model is AD-509T.
• Designed to fit the Holosun 509T footprint.
• The size is a lower 1/3 mount.
• Constructed from 6061 T6 aluminum.
• The finish is hard coat T3 Mil-Spec anodize.
• Features the Patented QD Auto Lock Lever system for positive engagement.
• The mount is a one-piece, precision-machined unit.
• The color is black.
• Functionally a quick release optic mount.

Engineered for reliable, repeatable mounting with minimal profile, the AD-509T supports configurations where a compact sight picture and quick tool-free removal are valued. Its quick-release interface and precise fit help maintain optical alignment across installation cycles, making it suitable for range use, competition, and compact duty or carry builds where consistent performance and dependable attachment are required.