The device (1) of a coating comprising a mat (2) and a housing (12), the mattress (2) comprising a core (6) and a cover (7) provided with an opening (8) for the insertion of the core (6) in the cover (7)； the cover (7) comprises an internal pocket (10) is coupled, in the manner of a flap, the cover (7) by a link (11) of the pivot hinge axis substantially parallel to the closure line formed by the portion of the fastener (9) to slide extending along a longitudinal side (5) of the mattress (2), said pocket (10) is housed in a removable manner, the housing (12), said housing (12) having a body (13), delimiting a chamber (14) able to communicate with the outside.
