A casing assembly includes a casing having a receiving space and an entrance, and a lid mounted detachably in the entrance to deny access into the space. The hard coating preparation has the hard coating layer containing any one of sugarsugar alcohols selected from the group of maltitol, xylitol, erythritol, mannitol, lactitol, PALATINIT, trehalose, sucrose, and oxidized starch andor acid treated starch. The wrist cuffs and ankle cuffs are both elastic and adjustable, to accommodate footwear and gloves of any size and thickness.