SKB 3I-4719-KBD Injection Molded 61-Note Keyboard Case Ultra high-strength polypropylene copolymer resin UV, solvent, corrosion and fungus resistant (MIL-STD-810F) Complete gasket seal makes these cases absolutely watertight (MIL-STD-C-4150J) with Automatic ambient pressure equalization value (MIL-STD-648C & IP67) Resistant to corrosion and impact damage Molded-in hinges