The first thing you notice about this device is the quality of the construction. The wood is high grade, the metal screw heavy gauge, reasonable leverage on the shoe. To work this device you simply screw it down to fit in the shoe. Depending on whether your attempting to widen or lengthen you twist 1) the handle will expand the front toe 2) the upper collar screw will expand the length. You can not do both at the same time. You either widen or lengthen. On either operation the device has very broad capability. The problem is your shoe has to cooperate. On a regular womens shoe I would look for more than half a size. It the leather is pliable maybe a little more. You can buy a bottle of leather stretcher spray (water and alcohol) or steam the tight section over a kettle (my preferred method). Over time (hours) you can slowly and very incrementally re-tighten to get the shoe bigger. The only two warnings I would give is 1) there is no way to know how large your making the shoe 2) the handle allows you to over torque the screw producing crunching sounds which I think means your breaking it.