AliMed Hot Packs provide up to 30 minutes of deep moist heat. Colored tabs allow for pack rotation. Reusable, each pack will last through hundreds of treatments. Heat in pot of hot water or Hydrocollator heating unit. AliMed Hot Pack Covers create an effective buffer between steam pack and skin. Hook and loop fasteners keep steam packs in place. Washable. Foam-Filled Terry Cloth with pockets. Polyurethane foam sandwiched between two layers of heavy-weight terry knit weave. All Terry Cloth version constructed with four layers of terry material. Brand-name quality at the right price!