Chilling unit effectively chills cold packs and keeps the packs in a chilled ready-to-use state. ColPaC C-5 mobile chilling unit with 6 standard and 6 half size cold packs has closed-cell foam insulation. Drain valve for easy cleaning and defrosting. Stainless steel, welded construction. Heavy-duty compressor. 3" (8 cm) swivel-type rubber casters for silent, friction-free movement of mobile units.