Trek Tumbler sugrörslock

The double-wall insulation actually keeps my iced coffee cold for hours, even when I forget it in the car. The four straw positions are a nice touch, too—I can flip it to either side depending on how I'm holding the mug.

The quarter-turn threading is genius—I can spin the straw to whichever side I'm holding the cup, and it clicks in place without any fiddling. My drink stayed cold through a whole afternoon of errands, which never happened with my old lid.

The double-wall insulation is the real deal—my iced coffee stayed icy from my morning commute all the way through lunch. Being able to rotate the straw to either side is such a small thing, but it makes drinking with my left hand feel completely natural. Probably the sturdiest lid I've owned.