Innate Americano Tumbler (340ml/11.5-Ounce) - 2012 Vacuum construction made with premium type 304, 18/8 stainless steel Keeps liquids warm up to five hours: preheat with hot water for best results Push-button steam release valve integrated into stopper for easy opening Proprietary ergonomic cap doubles as serving cup and features extra insulation for use on cold days