What is the difference between the Standard and Premium fixing sets?

Both are compatible M6 rack fixing sets for suitable square-hole rails. Standard is the economical conventional option with a 14mm screw and separate plastic washer.

Premium uses the fixing style supplied with our P Series cabinets. It has a 16mm screw, retained metal washer, cleaner screw finish, a wider lead-in chamfer on the nut and less movement in the floating nut. In our hands-on comparison the Premium screw also engaged noticeably more smoothly.