<p>The element (1) has a bendable stop spring (2) comprising a detent (3) that stays in locking engagement with a horizontal rod in a secured condition of the element. The spring is connected with a form-stiff actuating latch (4) that lies adjacent to a boundary latch (6) in another condition of the element. The spring is bent for detaching the locking engagement of the detent from the rod in the latter condition such that the detent is not locked with the rod. A support section (8) lies on the rod, and a fastening latch (10) runs parallel to a side wall.</p>
