measuring rim depth, Stinger 5, sounds right?

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I've been emailing w/ someone about buying some HED Stinger 5s. I just wanted to confirm that they are, in fact, the 5s and not the 4s, since there are so many 4s around from new bike take-offs. He measured the rim and says:

> From a nipple to the top of the rim where it meets the tire measures just over 50mm.

Does this sound right? The Stinger 5 is 50mm deep. As far as I know depth is usually measured only in one plane, such as you would do with calipers. I'm not 100% sure how he measured, but assuming he used a cloth tape on the rim, not calipers, is there any chance that the curvature of the rim is distorting this number? The Stinger 4 is 46mm, so w/ alot of shape is it conceivable that a measurement along the surface of the rim could make it seem like 50mm-ish?

I can, and probably will, ask for clarification, but before I do so I was wondering if anyone had any input, esp anyone w/ the Hed Singer 5s.