GRADUATED COMPRESSION TECHNOLOGY: Engineered compression sleeves to provide superior relief of shin splints, calf & lower leg pain and discomfort. Optimal support for muscle endurance and ultra-fast recovery. HIGH QUALITY BREATHABLE MATERIAL: Professional blended material (lycra & spandex) designed for cooling, breathability, and remarkable comfort. Designed by everyday athletes to be worn for all day comfort & all day compression. Perfect for pre, during, & post workouts. BOOST CIRCULATION: Superior support to aid in muscle recovery. Designed to prevent muscle fatigue and naturally improve your muscular endurance. OPTIMAL SIZING: These calf sleeves are suitable for men and women ranging from 5'2" to 6' in height with calf size (thick part of calves) between 12-16.5 inches. Important: Calf size is the KEY measurement for the best fit (wait for our XL range if you have larger calves). 100% BETTER THAN MONEY BACK GUARANTEE: If for any reason you don't absolutely love your endurance shield compression sleeves, just return them and we'll refund every single penny or send you a replacement! This is our iron-clad, best promise in the industry guarantee!