Abstract: A cassette system for window treatment includes a head rail with a base, end brackets attached to the base in a facing relationship and at least one roller blind with a mandrel and a decorative panel that is wound on the mandrel. The panel can be selectively drawn off the mandrel by rotation thereof. The end brackets are identical and mate with end plugs on the mandrel to rotationally support the roller blind. In an alternate embodiment, two or more roller blinds are supported by intermediate brackets or by an intermediate bracket and an end bracket. The end plugs on the madrel(s) have identical shapes to mate with respective legs on the end brackets.