More comfortable than open-spring correctors, the fully enclosed spring is more hygienic and no exposed mechanisms to impinge soft tissue. No reactivaton needed: the ‘‘out-of-the-box’’ installation is accomplished in one appointment, and forces are continuous until they are removed. Only 2 sizes to choose from per style: the universal design fits both sides of the mouth for simple inventory. Both Double Lock and Anchor Wire appliances can attach to either arch for Class II or III treatment.