(A-100 Impulse Laser Unit not included) The U-Wrap’s outside layer is soft polyester loop fabric that is Velcro hook compatible. The inside layer is soft fleece with a foam padded center. Elastic straps permit flexible size adjustments. The U-Wrap is available in two sizes: Medium (8.5″ x 14.5″) and Large (8.5″ x 17.5″). U-Wrap treats above and below the joint. Impulse laser may be mounted on side for during the day, and under pants or on top for night time sleep.