100% waterproof with rubber interior liners, steel pin hinge construction, thick ribbed walls for high impact resistance, and an adjustable pressure relief valve for airline transit. The HD (Heavy Duty) cases have snap-shut latches, a thick-grip handle for extra strength and durability, and each locking point is protected with steel for extra security. This waterproof case offers an extremely competitive choice for demanding applications. Diced foam in the base, flat piece on bottom, and convolute foam in the lid. --- Interior Dimensions: 11.75 x 9 x 5 inches (products are not tested for complete submersion underwater).