Pro-Tec S.I. Back Belt Features A Sacroiliac Compression Pad For Targeted Pain Relief. Sitting Or Standing For Long Periods Of Time Can Often Cause Sacroiliac Joint Syndrome (The Strain Or Tearing Of The S.I. Joint Ligaments), Which You May Call Lower Back Pain. The Ingenuity Of This Wraparound Back Support Is A Removable Pad That Provides Compression Right On Your Sacroiliac Joint, The Connection Between Your Tailbone (Sacrum) And Pelvic Bone (Ilium), So The Hips And Sacrum Become More Stable, Releasing Muscle Tension And Reducing Pain-Causing Strain To The Lower Back. Adjustable Tension Straps Let You Customize The Compression On Your S.I. Joint. Thanks To Strategically Placed Non-Slip Silicone Gel Strips, The Contoured, Low Profile Belt Stays In Place And You Can Comfortably Wear Under Clothing... All Day!