Wilson Ultralight Tennis Cap Hat White Adjustable. Take relief from the sun’s rays in the Wilson Ultralight Tennis Cap, a lightweight polyester mesh knit cap with perforated side and back panels for extra ventilation. An adjustable hook & loop closure in the back allows for optimal fit. Ultralight polyester mesh knit body with with perforated side and back panels for enhanced ventilation Lightweight and flexible brim Adjustable hook & loop back closure Composition: Polyester; Spandex D1-301