Those were grey trousers, with a front-/side zip fly front and a velcro, belt-like closure over it. The knees sported some interesting zips, and for my life I can’t imagine that those zips over the knees would have been comfortable in any possible way if he, for example, dropped to his knees on them. I don’t assume those zips to be closures for pockets – who would want *pockets* on his knees? – and I also can’t imagine what other use those zips could possibly have.