VMH1015 Features: * Knee heat therapy * Natural pain relief * Safe, Far Infrared Ray (FIR) Heat * Automatic 30-minute safety timer * Personalized temperature controller * Portable and on-the-go * Low voltage heating * Circumference of Knee: S/M: 12" - 18" * Circumference of Knee: L/XL: 18" - 23" Options: * Available in Small / Medium or Large / Extra Large sizes