OrthoFX uses a next generation of polymer, FXTetra™, to mold a series of aligners that fit over your teeth like a glove, applying gentle pressure on each tooth to create gentle movement over time. You’ll love that our next generation FXTetra aligners are COMFORTABLE: Created by three layers of material with an elastomeric layer in the middle. STAIN RESISTANT: Thanks to the harder polyester layers on the outside. SUPER INVISIBILITY POWERS: The ISO-refractive surface has a high level of adaption, which means no one will see you’re wearing them. You’ll wear each set of aligners for a week, approximately 22 hours a day.