Holosun HS510C Spacer, Lower 1/3 Co-Witness, Flat Dark Earth

The Holosun HS510C lower spacer for 1/3 co-witness height in Flat Dark Earth (part no. 510C-SPACER-FDE) lowers the HS510C reflex sight to align its dot with standard AR-height iron sights for a proper 1/3 co-witness setup, finished to match FDE-coated rifle builds. Holosun machines the spacer for a precise, direct, drop-in fit under the HS510C base. Among mounting-specific red dot mounts, this HS510C FDE spacer is a purpose-built accessory rather than a universal part.

Key Specifications

• The spacer is designed specifically for the HS510C, ensuring correct co-witness geometry.
• The mounting height configuration is 1/3 co-witness, positioning the dot to align with lowered iron sights.
• The finish is Flat Dark Earth, matching FDE-coated rifle builds.

Frequently Asked Questions

Is this spacer specific to the HS510C? Yes, it’s built for a direct fit under that model’s base.

Why choose the FDE finish? It matches Flat Dark Earth-coated rifle builds for a coordinated appearance.

Buy the Holosun HS510C Spacer, FDE

An FDE-finished HS510C set up for 1/3 co-witness gets the matching spacer here, machined to a direct fit. Order it from our Lubbock, Texas gun shop and it ships fast.