Endurance Arm Warmers - Made in the USA 83% Polyester/17% Spandex Machine wash cold, air dry Lightweight polyester/spandex arm warmers Great for spring and summer riding, no fleece or heavy weight fabric, Ideal for sun protection on hot days Size Chart: X-Small (bicep circumference 10, finished length 20.5, wrist circumference 5.75) | Small (bicep circumference 11, finished length 20.75, wrist circumference 6.5) | Medium (bicep circumference 12, finished length 21, wrist circumference 7.5) | Large (bicep circumference 13, finished length 21.5, wrist circumference 8) | X-Large (bicep circumference 14, finished length 21.75, wrist circumference 8.5) Thumbhole design and silicone gripper help to keep them in place during your ride or activity Easily removable and they pack very small to stash in a jersey pocket while not in use