Double Depth shoes have been technologically designed by Drew to benefit those with special foot care needs. These shoes are designed with extra space and with removable insoles for even more room to insert medically prescribed foot orthotics. And orthotics treat a variety of ailments. Often, Drew double depth shoes feature the proprietary Plus Fitting System, offering two removable insoles to allow for a more customized fit. Look for the box labeled "PF" on the product home page.