Rambler Travel Mug 20oz in NavyMade from high grade 18 8 stainless steel, the Rambler Mug is both puncture and rust resistant. Double wall vacuum insulation technology means that your drinks will be kept at their original stored temperature for as long as required, while also keeping your hands protected from the extremes of heat and cold held inside. The tapered design of the travel mug allows for it to be easily held in a car's cupholder.