The M-Tac baseball cap Flex Rip-Stop has a crown made of six panels sewn from a light, plain rip-stop fabric, with water- and mud-protective Teflon coating. The one-size-fits-all delivers a comfortable fit for most and can be adjusted with a velcro hoop&loop system on the back. The six ventilation eyelets on the top of the crown provide excellent breathability.
I ordered the hat for myself and now the whole family wants to wear it. We plan to order a few more if available.