I agree with Cyberdemon, this is probably not modeled, but it should not be too complicated (unlike something like the Jawbone UP bands, where the pattern is fluctuating and wrapping around a curved surface).
I gave it a quick shot in SolidWorks but as I see now, it isn't quite right. The way I have it, the long edges waver up and down, but it is straight in the rendering. I'd have to think a little more on how this actually could happen in 3d form, and maybe it isn't possible to physically model it the way that the rendering appears
(bump map magic).
1. Base sketch (pink) and vertical drivers (blue)
2. Pattered + mirrored base sketch -- not really necessary except for planning.
3. Two surface-lofts using the base sketch and vertical drivers.
4. Linear-patterned and mirrored twice.