Works as advertised, in fact better than every other antis print device I have tried. Not as uncomfortable as feared; a little difficult to get the initial bite pattern correct; jaw soreness is an issue, but manageable. Concerned about long-term effects from leachable chemicals that may be present in the plastic (none are detailed in the materials). Also not entirely clear what “FDA cleared” really means. Seems like a cheap marketing gimmick (i.e., it isn’t reassuring; it raises potentially unnecessary/unfair questions about the company’s honesty and science).