I had purchased a shoe stretcher before, but was disappointed with the construction.  I am a woman with hard to fit feet.  I can wear anywhere from a 9 W to a 10 M.  This stretcher barely fits in my shoes, but that is actually a good thing since the goal is to stretch the leather.  It is also made of hard wood and all of the mechanical moving parts are made of steel.  There is no plastic anywhere.  I believe this stretcher will last for years, and I can sand it down a little at a later date if needed.  This stretcher is more expensive, but worth it.

I had purchased a woman's 9 - 11 shoe stretcher listed here on Amazon that was not wide enough to stretch any of my shoes.  Every time I used it, I had to put wooden shims in the shoe along with it so the product would actually work - even in a 10 M shoe which it was advertised to work for.  It had a wooden base, and the moving parts were black and plastic.  After a few uses, the plastic nut broke, rendering the stretcher useless.  I think it broke so quickly in part because of the stress that was put on the device just to get it to work.  It was cheaper both in price and quality.