I've used the Cali Cap this past week and took it on 75km+ of running on treadmills, trails, night running, midday running, etc. I must say, I am so thoroughly impressed with the incredible quality, flexibility and runnability I experienced with this hat. It's hard for me to see if I'd use another hat whilst out in my runs and races. As a content creator on Instagram, I was a bit nervous about how the floppy the cap would be if I attached my camera to it, but when I did try it, I it so sturdy. Such an incredible blend of flexibility yet sturdiness blew me away. Absolutely recommend this cap to any runner you come across, cause this is a brilliant one!!