Even lighter thanks to new AEROLIGHT™ FEATHERWEIGHT INSULATION. The Stanley The Aerolight Transit Mug comes with a feather-light insulation that keeps your drinks warm for up to 6 hours and cold for 8 hours. With ice, you can even enjoy 30 hours of chilled drinks. Leak-proof, narrow enough for your car cup holder and stylish, this Stanley will accompany you on your adventures.