Springfield’s OSP (optical sight pistol) mounting system is similar to the GLOCK MOS system. It uses a series of thin steel plates to accept screws through your optic.
The pistol ships with three mounting plates that accept a Vortex Venom, Leupold DeltaPoint Pro, and Trijicon RMR optic footprint. The plates themselves are well machined and have a good male/female connection to the slide. They are secured in place with three screws as opposed to two like most systems. An additional three sets of screws are provided, too.

If you use the Hex Dragonfly red dot optic it mounts directly to the slide of the pistol without the need of an adapter plate. This affords the shooter the best line of sight possible for their red dot by being as close to the bore’s axis as can be.
The HEX Dragonfly red dot sight features a Springfield Standard footprint, or that of a Vortex Venom or Burris Fastfire, so while the Dragon fly is the ideal optic there are 3 additional plates i clyded to mount the optic of your choice.