The 11-2 cap features T8 stretchable polyester twill that creates a refined look and flexible fit. The exclusive star product OTTO FLEX sweatband features elastic fabric that adapts to various head sizes for a snug, comfortable fit. The moisture-wicking and UV Guard technology keep you cool and protected., Key Product Features. T8 Stretchable Polyester Twill - Ultra-smooth texture with enhanced stretch. Has more stretch than T4 fabric Dual-Side Fabric - Twill weave on both sides for a smoother, high-end feel Moisture Wicking UV Guard Technology - Wicks away sweat and blocks harmful UV rays Enclosed Back - Clean, fitted design for a streamlined look OTTO FLEX Stretchable Sweatband - A snug, flexible fit with antibacterial, anti-odor and moisture wicking properties