There are 3 extenders in each package.The purpose of the extender is to make the three arms of the splint longer. Before you buy the extenders please try stretching the arms out first. Because they are elastic they will stretch out a bit. Maybe just enough to fit you. Usually after a couple of weeks the arms need to be made smaller. They can be used during pregnancy when your back size stays the same but the arms of the splint need to grow to accommodate for your growing belly. It will add from 8 to 12 more inches on the arms. Also, if your back measures a smaller size then your belly you will need to get the extenders until your belly gets smaller.
Each of the extenders should be attached to the Velcro tab of each of the three arms. The Velcro tab of the splint arm can be placed in multiple positions on the extender to make it smaller or larger.
Continuously attaching and then detaching the two sides of the Velcro (hook and loop) will cause it to lose its effectiveness.