Exos FORM™ II 621 SI Joint Back BraceExos FORM II 621 SI Joint Back Brace This belt is for SI (sacroiliac) pain and dysfunction and lower back pain and strains. It helps relieve pain resulting from standing or sitting for extended periods of time while supporting the hips. The Exos FORM II 621 provides superior stabilization of the sacroiliac (SI) joint through direct compression. Silicone grip strips prevent the brace from migrating. The Exos FORM II 621 compresses the sacroiliac joints