This case is built to precise weatherproofing standards, with a rubber seal and steel back that prevents dust build up and remains dry even in the fiercest of rainstorms. Thick toughened glass provides even more protection. The door features a lock and two keys for securing the display case against tampering, so you can display important messages in all environments. Designed primarily for A4 sheets, this product even comes with 4mm toughened glass for that extra level of protection.