The inelastic panels of the brace are 100% polyester Relieve Discomfort. The Aspen Lumbar Support can help ease low back pain caused by acute flare-ups, spasms, or fatigued muscles. This inelastic brace is a low-cost, medical-grade treatment option that features Aspens patented 4:1 tightening system for enhanced support. Easy to Wear. This brace is comfortable enough for extended wear and can easily be worn under clothing. Size Variety. This brace comes in six sizes. These sizes run small, so size up if needed. Easy Adjusting. The patented 4:1 tightening mechanism allows the patient to independently adjust the top and bottom of the brace to provide localized compression where needed.