Cast Aluminum Combo Boot Instep Shaft Stretcher-Stretches the calf (top) of the boot, The Cast Aluminum Combination Boot Instep and Shaft Stretcher is a high-performance, professional device for stretching the instep of your boot and the shaft. The instep and shaft can both be stretched in one process, or each area can be stretched separately. The Cast Aluminum Combination Boot Instep and Shaft Stretcher gradually stretches the boot shaft and/or the instep and relieves tightness around calf muscles. This heavy-duty product is perfect for the use on Western, Work, and Riding Boots.