Amazon offers the Contigo 20-oz. West Loop Autoseal Mug in Stainless Steel for $16.29. Clip the $5.43 coupon on the product page to cut that to $10.86. Plus, Prime members qualify for free shipping. That's the lowest price we could find by $5, although it was a buck less in May. It purports to keep liquids hot for up to seven hours or cold for up to 18 hours and features a push-button top.