Fou Fit Cooling Collar Red A completely unique and innovative way to keep your pet cool during warm weather or if they dislike the heat in your home. When you submerge this cooling collar in water, the special gel beads inside the product will begin to absorb and hold the water as it transforms into a gel. As the water slowly evaporates, it draws heat from your dog and cools them. Since dogs do not have sweat glands, the cooling collar mimics that process of cooling through evaporation. The cooling collar stays cool for up to 3 days with no drips! These collars are reusable 30+ times and are suitable for handwashing. Small 14″ x 2.5″. Medium 17″ x 3″. Large 20.5″ x 3.25.