My new Salsa Seatpost. . .
is slicker'n snake snot, and easier to adjust than advertised. For what it's worth, I ordered the longest (410mm) to be sure it would be enough. It's more than long enough, but didn't need trimming. It just slid down a bit farther than Salsa probably visualized.
Jensen USA is a pretty fast shipper, too. Former machinist that I am, I badly mismeasured the clamp, and it's probably not worth the postage to return it. I bet I did a bad conversion from english calipers to metric system.
Some people are like a Slinky ... not really good for anything, but you still can't help but smile when you shove them down the stairs.