Generally, the rails are Aluminum rail, and due to their shapes, they are used with different mid/end clamp and screw.

As below two rails, SIC-RA and SIC-R0 , both of them are used with SIC-IC/EC and tilt-in module.

And below two rails (SIC-R2 and SIC-R3)are used with SIC-IC-P which can be pressed into the rail directly and the hexagon bolt.

The two rails are rather popular in European market.