FIG. 1 is a left side view of a roller blind cassette of the claimed design;
FIG. 2 is an isometric top back left view of a roller blind cassette of the claimed design;
FIG. 3 is an isometric top front left view of a roller blind cassette of the claimed design;
FIG. 4 is a bottom view of a roller blind cassette of the claimed design;
FIG. 5 is a top view of a roller blind cassette of the claimed design; and,
FIG. 6 is a back view of a roller blind cassette of the claimed design.
The broken lines in the drawings forming other elements of a roller blind cassette illustrate environmental subject matter that forms no part of the claimed design. The break lines symbolize breaks in the length of the article in which the claimed design is embodied. The appearance of any portion of the article between the break lines forms no part of the claimed design.