This is the lumbar support brace that combines clinically proven heat therapy with compression for pain relief from arthritis, injuries, sacroiliac joint problems, and other conditions. While exerting gentle pressure, the three-dimensional lining creates a micro-climate that maintains elevated skin temperatures while wicking away moisture and promoting healthy air flow. It secures with hook-and-loop fasteners and has a low profile design for under clothing comfort. Sizes M (waist 32"-35 1/2"), L (35 3/4"-39 1/2"), XL (39 3/4"-44"), and 2XL (44 1/4"-48 1/2").