Close your eyes. Think jeans. Now open. They were 501s®, right? They're literally the blueprint for every pair of jeans in existence burned into the world's collective cortex ever since Levi Strauss (the man himself!) invented them in 1873. To this day they they've never gone out of style. And they never will.
97% COTTON, 2% POLYESTER, 1% ELASTANE (LYCRA)