The Cho Pat Upper Arm Support Strap prevents tricep tendonitis and helps relieve tricep and bicep tendonitis pain. This forearm support strap prevents the pulling and tearing of tendons and muscles in the upper arm. The Cho-Pat Upper Arm Strap is recommended for swimmers and other sports enthusiasts who may develop painful bicep or tricep tendonitis. This waterproof upper arm muscle stabilizer stays in place and absorbs and diffuses stress for optimal relief and comfort. The bicep strap is worn just above the bicep or tricep and acts as a compression device to prevent muscle and tendon tearing. This support strap is available in a range of sizes for the perfect fit. In order to get the right size and have the best results, please make sure you measure the circumference of your arm above your bicep. Match that measurement, in inches, to its corresponding size. Please note: If you're between sizes, we suggest you order the smaller size.