You can't go past our amazing 20 oz Tumblers! These are made from food grade stainless steel and can be used either hot or cold. I have tested this myself and ice didn't completely melt until 12 hours past. This was on a 44 deg Aussie day! I suggest you buy a handle if you buy this! The handles and Magslider lids are available to purchase Separately! Note the green camo ones are on back order and should arrive within a week!