AliMed Side-Lying Hip Abductor keeps knees bent at 90 degrees and abducted to externally rotate the hip. FeaturesExcellent for hip abductor spasticity. Reduces bone-to-bone pressure. New Waterproof model is wipe-clean, coated polyfoam. Great for incontinent patients. Use over and over again. Straps for Waterproof model sold separately. SizingMeasure inseam crotch to bottom of foot with leg straight . Std., inseam greater than 30 Sm. Foam only , inseam 30 and less. SpecificationsStd. Foam, 14 W x 14 D x 9 H inside curve to 11 H outside curve , four 2 W straps Sm. Foam, 12-1/4 W x 12-1/4 D x 9 H inside curve to 11 H outside curve , four 1-1/2 straps Std. Waterproof, same size as Std. Foam, four 2 W straps sold separately 1 Each / Each