These 10cm selenite sticks can be used to cleanse other crystals in it's vicinity by placing small pieces on or around them.
Alternatively, these sticks can be used to cleanse and sweep the aura of any stagnant or negative energy. 
Additionally, this form of gypsum is said to help with a restful nights sleep, regulate the menstrual cycle and may help with fertility issues.
 
The piece you receive will be between 15-21mm in thickness.