12×12 mat —
10.90″ × 9.91″
B20.04.00.00.001 with a lid. Every corner closes on a diagonal fold — a web — and the two side walls fold back down inside themselves, locking behind tongues slit into the base. Two tabs stand above each side wall and rise through the base of the tray above. The lid hinges off the back wall and tucks in at the front on a wall of its own, half the tray's at most so its corner flaps clear the webs; notched at each tab, it lies flat and cannot slide. Ours, not a catalogue code.