How long does ice water stay cold in this tumbler?

Our double-wall vacuum insulation creates an airless barrier that dramatically slows thermal transfer. In real-world Dubai conditions, expect ice to last 8-12 hours and cold water temperature to be maintained for a full 24 hours. For maximum ice retention, pre-chill the tumbler with cold water for 5 minutes before filling. The exterior remains completely dry and room-temperature regardless of internal cold.