Install the HE509T directly to your 9mm or .40 MOS slide with the Holosun 509 Adapter for MOS and save rail space. These Red Dot Sight Mounts designed by the experts at Holosun are specifically designed to fit the HE509T red dot sight, which uses a re-zeroing target after sight alignment. Using the Holosun HE509T Adapter Plate greatly increases the accuracy of your pistol - a sight that's especially good for beginners in the field since it doesn't require as much sight adjustment as other optics systems. This 1 oz. steel plate ensures the Holosun 509 HE509T Adapter for MOS Slide will hold up under all the recoil you deliver. When you need to mount a sight to your pistol, this Holosun 509 MOS Adapter Plate is a necessary tool for the job. Speed up your acquisition time and ensure a tighter tolerance than ever before by using this Holosun 509 HE509T Adapter Plate. Specifications for Holosun 509 Adapter for MOS: Manufacturer: Holosun Red Dot Sights-Footprint: Holosun 509T Optic Cut: Holosun HE509T Fabric/Material: Steel Color: Black Fit: Glock Modular Optic System Length: 1.9 in Attachment Type: Slide Weight: 1 oz Height: 0.15 in Gun Make: Glock Gun Type: Pistol Width: 1 in Condition: New Features of Holosun 509 Adapter For MOS: 1 oz Steel Plate MOS slide to HE509T interface Package Contents: Holosun 509 Adapter For MOS