#zspring 

This video is about wire bending for making of z-spring
also known as double cantilever spring
All the photographs are taken from "Orthodontics , The Art And Science " by "S.I. Bhalajhi" 7th edition
It is an active component of removable orthodontic appliance (palatally situated). It is used for mesiodistal movement of any tooth (incisors, canines, premolars and even molars) which is located within the line of the arch. However, it is mostly used for distal movement of canines.