The Phiten MLB Authentic Collection Power Sleeve, featuring Phiten"s Aqua-Titanium technology are worn by Major League Baseball players on the field. Designed for additional support for your elbow and made with moisture-wicking fabric to draw out sweat, this sleeve is made for superior comfort so you can focus on your play on the field. The Phiten MLB Authentic CollectionTM Power Sleeve is made with nylon and polyurethane blended fabric permeated with Aqua-Titanium. The Official MLB Batters Logo is printed on the lower part of the sleeve and Phiten P logo is placed on the middle of the sleeve. Sold individually, for use on 1 arm The ENERGY TRASNPORT SYSTEM present in all Phiten products stabilizes the body"s energy flow Aqua-Titanium is permeated into fabric just like dye; each strand becomes permanently embedded with Titanium nano-particles Reinforced flat-seam lines along muscles Quick-dry fabric Compression fit for support Sizing: Small: 7.5" Bicep/5.5" Medium: 9" Bicep/6" Large: 10.25" Bicep/7" XL: 11.5" Bicep/7.5" Note: Will stretch 2-3 inches