Map Case LargeMap Case Large is a waterproof map case with internal dimensions 265x480 mm mm that fits Olympic maps. It is transparent on both sides and can be attached to your kayak or backpack. The map case is made of durable TPU material and is also touch screen compatible. Strong waterproof map case for OS maps with roll top closure Map Case Large is made of a strong and durable 0. 3 mm TPU PU material with roll top closure and is waterproof according to IPX7.