The square lid consists of two triangular parts, so that the opening is done by lifting one of the parts
This lid sometimes also appears as a pair of (modular) lids, as seen in the lids photographed in 2024 at 40 Bd de Sébastopol, 75001 Paris, France Click for a larger image
Translation of the text on the cover: ACIER MOULE - MOLDED STEEL