Includes Sweat Liner D Each Hat Pros Flexfit cap includes a peel-and-stick sweat absorbing liner that helps wick away sweat, improve wearable performance, and keep your hat cleaner, longer. 97% Polyester / 3% Spandex Look & feel of wool. Moisture wicking. Superior drying. Hard buckram. Hypoallergenic. Matching undervisor. Form-Fiting Stretch Fit – Designed with a built-in Flexfit stretchable sweatband, these versatile baseball caps ofer better breatherability and an improved fit for heads of all sizes.