Reduce Cold1 24-oz Tumbler Set Double-walled, vacuum-insulated construction keeps drinks cold for up to 24 hours. Made of food-grade 18/8 stainless steel and BPA-free. The patented 3-in-1 "Sip-It-Your-Way" lid allows you to sip, sip, or gulp down your drink. Fits most car cup holders and is dishwasher safe. Interior hydration markers help track your hydration levels.