This service is to convert your 43XMOS/48MOS existing optic cut to accept a Holosun 407k/507k/EPSCarry.
This conversion includes a set of custom M4x.7 screws.
If you don’t want to run an optic plate this is the cut for you. It runs nice and deep so you can still use your factory sights, no need to get something for a cowitness. Overall excellent cut and probably the best nitride finish I’ve seen from an aftermarket company.