In our efforts to create what is the worlds best- Shark Tank & Award Winning- no-tie shoelaces in the entire world, we first had to be become experts in sneaker design.  We've studied literally thousands of pairs of sneakers in an effort to really understand how they are made and particularly how they are strapped to the foot. Before we go further we need to define a term we call 'eyelet-span’. Eyelet span is the distance between adjacent eyelets on a sneaker. This is an across the top of the foot measurement. What we’ve found in the process of measuring thousands of pairs of sneakers is that there 3-4 prominent eyelet spans that are utilized by nearly every sneaker brand in the world. The lengths of uLace Classic, Kiddos, Slims and Shorts were designed to match those eyelet spans. This matters because most of the copycat products on the market are first of all: made from cheap nonflexible plastic or silicone that are impossible to install yet to easily break, but also sold as one-size-fits-all products which actually don't fit any sneakers well.