These shoe covers were also very large.  I got the child's large for my 7 yr old wears size 12.5 shoe... these were huge on him.  These fit over my grown kid's shoe size 8.5.  There are 2 bread elastic straps underneath that get destroyed quite easily.  But I am able to sew back on.  Also, I have washed these a couple of times in cold water on regular wash cycle no problem.  A must but if you want the complete astronaut outfit.