Review on DEWALT Stainless Steel Tumbler Review: Yellow, 30 Ounce Capacity, Durable & Reliable by Darin Marshall

Mech. Doesn't matter. Basically does what it's supposed to. Doesn't leak like a truck driver who has a hard time finding a coffee mug to say that about. I'd be thrilled, but the little flip cap locks securely and prevents said leaks, but doesn't latch securely. I have to hold it with my finger (while driving) to keep it in place and not come back to hit me. Which he did, one of the first times my wife watched me. She made fun of it and me. But she's just mad because I bought that instead of what she bought me.