This product is brought to us by our friends at AMMJ. We're just a hub for them to supply they're product through. The rails are compatible with our mounts, and hardware will be included to make that applicable. Below is the description provided for us by AMMJ. Design Machine can answer most questions. However, since it is not our product, we suggest any questions regarding the M-Lock side rail be addressed to AMMJ, their contact info is below the product description.
AMMJ Partial M-Lock panel for P90/PS90.
The M-lock segment can be mounted to the upper receiver of a P90 or PS90 using the existing threaded holes as a channel to mount directly into Design Machines low mounts. Originally this segment of M-Lock rail was made to be used with the Design Machine series of optics mounts for a sleek update to the firearm.
With the M-lock system being so wide spread it lends itself to simple things like; a QD mounting point up front and up out of the way of the charging handle, mounting a variety of low profile light mounts with lights without interfering with the magazine, offsetting M-lock pick rails or using longer pick rails pushing accessories even further with no other specialized adapters.
Allows M-Lock designated accessories to work with the PS90, giving you the option of M-lock instead of Picatinny style on the side. Also for people that enjoy making they're guns aesthetically pleasing, the M-Lock Rails look great!
Marvin Quezada Jr (President AMMJ)