Hi Paul, Thank you for reaching out to us. The Navy Low profile cap max is 8.5 adjustment. Low profile is also lower profile meaning it sits closer to your head and not as deep as a structured cap. If you are larger than a 8 1/2 then I recommend for baseball cap the 4XL/5XL Delta FlexFit caps. I have a link below. Don't hesitate with any questions. ~ Fran
https://www.bigheadcaps.com/4XL-FlexFit%C2%AE-Caps_c_89.html