Epi-Lock Strap® features a unique patented 2 strap system. The strap near the elbow supports deeply buried extensors and works with the forearm strap to provide exceptional support and pain relief. The non-elastic straps are worn comfortably snug. When muscular force is applied, the extensors automatically enlarge, causing the straps to tighten. Universal Left or Right strap. Measure forearm circumference for sizing. Non-Returnable.