The automatic pressure equalization valve allows air to flow in and out of the case while still maintaining a waterproof seal The 4-piece foam set consists of one 'egg crate' foam upper section, 2 Pick N Pluck foam sections and one 1' blank bottom foam section. The Pick N Pluck sections allow you to customize the foam to snugly fit your gear into the case to maximize protection and minimize movement during travel The top and side handles are over-molded with rubber for added comfort when carrying the case Stabilizing blocks are built-in so you can lay the case down flat when accessing your equipment Withstands temperatures from -40 to 210deg.F