LONG-LASTING COOLING: Freeze for 4-6 hours and they will keep your lunch, breastmilk, or drinks cold for 6-8 hours. 100% LEAK-PROOF: Double-sealed, welded seam construction prevents any gel from leaking onto your food. The , seamless exterior is easy to wipe clean and will not absorb food odors. PREMIUM STAINLESS STEEL: Made from high-quality 304 stainless steel that is rust-proof, shatter-proof, and dent-resistant. These rounds will not crack or leak after repeated freezing and thawing. MULTI-PURPOSE COOLING: Use them to keep your salad crisp, your yogurt cold, or as gentle cold packs for sore muscles (wrap in a towel). SPACE-SAVING ROUND DESIGN: The flat, disc-shaped (approx 3.74 inches diameter, 0.97 inch thick) fits perfectly on of food or under containers in bento boxes, round containers, and cooler corners. Maximizes surface contact for even cooling.