Flip open, sip and close up tight. The leakproof Transit Flip Top Mug is lightweight, slim and made for your commute. Drop in your backpack or bag, or slide it into most car cupholders. It's ready to travel. The 20-ounce Transit Flip Top Mug has premium AeroLight technology that makes it significantly lighter than standard stainless steel. Featherweight spun-steel with vacuum insulation keeps your drink at the right temperature for hours. Matching soft silicone at the lid tab and footpad makes opening, closing and set downs quieter.