My thermos flask worked fine for a few months until it suddenly stopped keeping the heat in entirely. How do vacuum flasks stop working? - Quora
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Amazon.com: Stainless Steel Thermos Cup, SUPKIT 12oz Small Thermos Vacuum Cup, BPA Free, Insulated Water Bottle Keep Hot & Cold for Hours, Perfect for Biking, Camping, Office, Car or Outdoor Travel (Taro
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