Stainless steel, Tritan. Wide twist-off top lets you add ice or protein powder quickly and easily. Use as a vacuum-insulated water bottle during your workout and as a tumbler before or after. Twist-off Tritan top is shatter-, stain- and odor-resistant and converts bottle into 18 oz. tumbler. Stainless steel and vacuum-insulated for maximum temperature retention - keeps beverages cold for 12 hours. Non-slip silicone bottom provides quiet set-down on any surface. Carry loop for easy transport. Large opening for easy fill and cleaning with twist-to-seal lid that helps keep spout clean. Stainless steel BPA and lead-free.