Although the Levi's 505 jean is usually referred to as the zipper version of the classic button fly 501, the Levi's 512 model seems closer to me. If you are looking for the 501 fit without the hassle of buttons, this may be the way to go. The 505 is rather full in the seat and crotch (technically "the rise") and can look pretty baggy. Though described as a "slim fit", the 512 is more of a moderate fit, snug but not formfitting, much like the handsome 501. Rather than slim fit, it really should be described as the 512 "tapered leg", because it has a noticeable taper to the ankle, which means it will not fit over boots, unlike the 505 and the 501. The denim is thick and of good quality, and breaks in nicely over time. However, if you really do want a true slim cut -- the 514 is better choice as it is trimmer in the seat and sits a little lower on the waist.