The Wilson 3D Multi Action Expander is a fixed/removable appliance that allows you to remove the appliance without removing the bands so you can adjust it. The patient can not remove it. Works great as a retainer after Rapid Palatal Expansion or other upper arch development. Find out more about this appliance at: https://ohlendorfappliancelab.com/app... This is a Rocky Mountain Orthodontics, RMO product.