20oz Double walled Hydro Flask Bottle. Unique TempShield double-wall insulation protects temperature for up to 24 hours cold and 6 hours hot. Honeycomb insulation inside lid for additional temperature control. 18/8 stainless steel construction is durable and won't retain or transfer flavors, and is tough for any adventure! Also BPA free. Comes with a leak-proof black lid with a carrying handle.