Fit Bandit, Non Slip Sports Headband for Exercise, Green Zebra Patent Pending, Design Has an Elastic Gripper Sewn Inside for a No Slip, Snug Fit That Stays in Place During Exercise The Secret to A Perfect Fit is To Measure Your Hairline. We Offer 3 Sizes to Ensure a Comfortable, Snug Fit Use a Soft Tape Measure or (Ribbon & Match up to a Ruler) & Measure Your Hairline. Small is 17" to 20", Medium is 20.1" to 22" and Large is 22.1" to 24" Fit Bandit Headbands Do Not Fray or Unravel Because They Are Sewn on Both Ends & Lay Flat Because They Are Tapered in the Back, Made in the USA So Durable You Can Machine Wash & Dry or Hand Wash & Air Dry