Anti-slip shower tray was found to be a little shorter than the 1100 mm to match the 1100 mm x 900 shower cubicle that we had, but we overcome this by filling in around the tray with plasterboard adhesive then fitting no leaks sealant tape to cover adhesive when it had set & onto tray itself, then fitted shower panels on to tape, sealed around panels & tray next day with anti-mould sealant, cubicle had the correct fitting clearances, job done, tray is great with the anti-slip as you cannot slip ...