X-Small fits waist circum. 23.5 -27.25 (when sizing measure around the middle of the waist) * Provides pain relief and compression for muscle injuries and general lower back dysfunctions; injuries to the lumbar discs and the sacro-illiac joint * Has 2 internal flexible metal stays for support and adjustable elastic side straps * Captures body heat & increases blood flow * Allows skin to ventilate and release moisture