A set of DIN Rail end clips. They have holes for an off-center compression screw, two holes for T-nut mounting, and 1 or 2 holes (depending on he model) as retaining/guide screw(s). All screws are M3.

They can fit both single and double lip DIN Rails. You can either use a screw and a nut for the guide screws or use heat-seated nuts on the bottom support lip.