Activating Palatal Expanders
A palatal expander or RPE is used to widen the upper jaw so that the bottom and upper teeth will fit together better.
To activate the expander place the key in the center hole and urn in the direction of the arrows that are on the expander. Turn the expander toward the back of the mouth until you can see the next hole. Carefully remove the key in a down-and-back direction, while being careful not to un-turn the expander when removing the key.