We bought this recently and started to put it together On coming to the point where you fit the lid we thought we were missing the part  WLBM We then realised the part had been supplied slotted into the groove in the base so we had to take the shed apart again to get to this piece It was our fault but just be aware to remove this before you fit the side pieces and the back The shed had still gone together with this stored in the groove in the base and we did end up damaging one of the screw holes when taking it to pieces Apart from this we really like the product