Beware - These disposable shoe stretchers are one-time use only. As long as you don't twist the stretchers more than 1 or 2 "hard turns" you can use them one time and thereafter, it is straight to the recycle bin. Should you try to turn a bit harder on your first use for a firm stretch, their thread on the cheap plastic screw will strip almost immediately.
If you use them lightly one time then on your 2nd time around you will experience the disintegration of the internal plastic components (which spread the wood to stretch). Spare your hard-earned money and buy a good quality, well-rated shoe stretcher with wood and steel components.