Chaco collaborated with the NPF to create special, limited-edition sandals to support national parks. I can't recall if it was Grand Canyon, Arches, Canyonlands, it was a desert park though. Super supportive and stable for long hikes. Great for traversing trails with water crossings. I like the more secure fit of the toe loop vs the band of Z/1. I only got couple uses out of them on one trip and after I washed them, they barely show any wear at all. They are super supportive and are ready the full life they did not receive from me. I had never seen limited edition offered on poshmark or any where else. Happy to bring it you. I worked at REI for a short time and everyone had these. Employees and customers lol. I felt like they were issued with your membership. They are excellent for life outdoors, hiking, camping, on the way to climbing, versatile for backpacking (and supportive even with a heavy pack), traveling, from the beach to the desert and everything in between.