88% POLYESTER. 12% SPANDEX. THIS PERFORMANCE MIDLAYER OFFERS A FOUR WAY STRETCH SHELL ALLWOING FOR FREE RANGE OF MOTION THROUGHOUT THE GOLF SWING. EASY TO CARE FOR FABRIC IS MACHINE WASHABLE WITH MINIMAL WRINKLING OR SHRINKAGE. THIS ANTI-MICROBIAL FINISH HELPS INHIBIT ODOR BUILD-UP WHEN AMBIENT MOISTURE IS PRESENT. FJ LOGO ON BACK YOKE.