This Knee Spreader Abduction Wedge prevents hip adduction that can result in dislocation following hip arthroplasty. Important for post-op in recovery wheelchair users. Comfortably maintains 4" of knee separation. Adult model knee abduction wedge is available in high-density foam with machine washable, blue terry cloth cover or waterproof closed-cell foam. Pediatric knee abduction wedge model is closed-cell foam- impervious to liquid (doesn't include cover). Hook-and-loop strap maintains knee separation position, 4"W x 36"L.