1 PCS Orthodontic Cheek Enlargement Retractor Intraoral Lip and Cheek Retractor Soft Silicone Opener High Temperature Resistantcharacteristics;1. Material: soft silicone material, comfortable to wear2. It can be sterilized at 135℃, and can be sterilized by high temperature and high pressure repeatedly.Specification:Function: openerApplicable object: adultsPackage list:1* Mouth Opener