The 40oz Thermos® Stainless Steel Cup Holder Mug is engineered to fit oversized car cup holders — the ones that standard bottles fall through. Vacuum insulation keeps drinks cold for up to 24 hours. BPA-free stainless steel with a sweat-proof exterior. The slim base fits most standard and oversized cup holders. Perfect for long commutes, road trips, and stadium days. Specifications: 40oz capacity | Vacuum insulated | BPA-free stainless steel | Keeps drinks cold 24 hours | Fits oversized cup holders | Sweat-proof exterior Double-wall vacuum insulation keeps drinks cold 24 hours by eliminating heat transfer between the environment and the contents. The vacuum space between the two stainless steel walls means no conduction, no convection — just consistent temperature from fill to finish. BPA-free 18/8 stainless steel. Dishwasher safe — top rack only. Shop all Thermos® drinkware , view best sellers , or add laser engraving .