Abstract: A stair nosing (1) including a window (3) and an L-shaped member (2) configured to display one or more signs (50) protected by the window (3), the L-shaped member (2) being configured to releasably retain the window (3); said L-shaped member (2) including a first section (4) and a second section (5) respectively configured to form all or part of the tread and the riser of a step once installed; the first section (4) and second section (5) being connected by at least one hinge (67) that extends parallel to the length of the stair nosing (1), said hinge (67) being configured to allow an interior angle formed between the sections (4, 5) to be varied over a preset range.