Blue Jay Lumbar Support SM Small 27.5 31.75 Blue Jay Narcotic Safes doctor's advice information MSHQ 22030C doctor's advice information 3 MHz applicator * All three applicators can be stored on the unit itself to keep them available at all times * The Sonicator 740 is 1 and 3 MHz therapeutic ultrasound unit which comes with a 5 cm˝ dual frequency applicator * It is light weight and portable and features a universal applicator cable to make changing applicators quick and easy * There is an optional rechargeable lithium ion battery pack that truly allows you to take therapy on the road with you * Large soft touch controls let you set up treatments quickly and easily and the backlit display shows all treatment parameters and conditions * Weight: 3 Small fits waist circum 75 (when sizing measure around the middle of the waist) * Provides pain relief and compression for muscle injuries and general lower back dysfunctions