Hydro Flask 40oz Traveler Tumbler $20

Hydro Flask's 40oz Clear Lid Travel Tumbler in Harbor Blue is on Woot for $19.99, a 56% discount off the reference price. Its double wall vacuum insulation keeps drinks cold for hours, while the leak resistant lid and flexible straw make it easy to sip on the go. A strong ergonomic handle makes it simple to carry, and the design still fits most cupholders, so it works just as well in the car as it does at the gym or the beach. It sells for $24-$50 at other sites.