hydro flask, bottle wide mouth flex cap cobalt 18 ounce hydro flask hydro flask temp shield 18-ounce wide mouth tumbler regulates the temperature of your drinks for hours for a fresher, better taste. our unique double wall insulation keeps cold drinks cold and hot drinks hot while the sweat-free design makes the tumbler ideal for working out and taking on the go. this package contains one 18-ounce wide mouth tumbler.