I think this one has come up before, but I could be mistaken. To be honest, in looking at the picture, it looks exactly like a pair of khaki shorts with the seams at the crotch removed and single width cloth replacing it. It actually looks very comfortable, although I can't comment on the compatibility with a backpack. Hmmh, and for $35, might be worth a shot. I spent way more than that on my first SK and I rarely wear that anymore as it wrinkles so easily, but looks nice enough that it demands to be ironed.

Dang, just checked and they only have the small size!