I stumbled on this shoe size measuring device on Amazon by accident.  Throughout the years I have seen them in shoe stores and department stores.  But with the advent of online shoe sales, this is now extremely practical for home use.  The combination mens/women's device is great.  No reason to buy a separate one for each.  It is made of metal, like the original design when it was invented way before my time.  This is a quality product that will outlive anyone reading this.  It is also something that is timeless and future generations will be able to use it.  Another reason you would want your own device is your foot size changes depending on your activity and measuring it after exercising is perfect for gym shoes, running shoes or dance shoes.  The measurements from this device are what shoe manufactures use to create shoes.  This not only measures the length but the critically important arch measurement.  The arch measurement could change the overall shoe size.  This device also measures the foot width all at the same time.  This is important to prevent you from buying a shoe too narrow or too wide.  If you have children and buy shoes online, I would also recommend buying the one for children's shoes.  You will also be surprised to find out your exact shoe size.  You are probably wearing shoes that are sloppy on your feet.  A properly fitted shoe is critically important for running or dancing.  Now keep in mind that there are variances in how manufactures design shoes so an individual shoe may note fit perfectly.  But this measurement will get you very close to perfection.  I highly recommend this product.