Though not as popular as NATOs, perlons are of a similar ilk: Made of woven nylon, they pass between the spring bars on your watch and lay flat against the watch’s caseback. Unlike NATOs, however, they only have one length of fabric, meaning the watch head sits much closer to one’s wrist. Also, unlike NATOS, perlons are braided from small nylon loops — rather than one, tightly woven length — making for a different feeling against the skin. They’re also fast-drying, and because of how they’re woven, can be adjusted to nearly any size along the length of the strap.