The AquaGuard sheet is a waterproof disposable moisture barrier which keeps sites, wounds and dressings dry while the patient showers. AquaGuard features a specially designed medical adhesive that effectively protects the area from water while you shower and is gentle during removal. The actual area of coverage is 7" x 7.5" (18cm x 19cm). Please measure your site/dressing to make sure it fits within the actual area of coverage. One sheet is needed for each shower.