Sweet. How cool would these be on your next camping trip? Walmart has the Ozark Trail 12oz Vacuum Insulated Stainless Steel Mug, Set of 3 for only $14.99! (Reg. $45) The Ozark Trail 12oz stainless steel vacuum insulated handled mug will keep your drinks cold or hot for hours. The exterior wall of the inner lining is plated in copper for superior temperature retention and will help prevent your bottle from sweating.