Before operation, dentists need to put the retarctors on both sides of patient's lips to maintain the mouth opening so that patient will not feel too tired. Meanwhile the tongue guard can effectively restrict the activities of the tongue. The mouth bottom is just below the suction area, which can maximize the absorption of the saliva and prevent moisture. This product can create a relatively dry environment for dentists. It's mainly used for orthodontic treatment. Dental Dry System keeps the mouth dry while isolating arches from tongue and cheeks. Combined into each appliance is an adjustable cheek retractor, saliva ejector, tongue guard and low-volume suction connection. Inlets are shielded for uninterrupted evacuation. Specially designed not to cover occlusal surfaces of the teeth. Great for sealants, ortho bonding, and posterior restorations. High-heat plastic and silicone construction autoclavable to 280F. Simple assembly required. ?Package included: 2 main body 1 Manual?Autoclavable Material?High-heat resistance plastic and silicone construction is durable, without being out of shape or breaking even after twisting bending, pulling and folding. ?Application?Specially designed not to cover occlusal surfaces of the teeth.Inlets are shielded for uninterrupted evacuation.Great for sealants, ortho bonding, and posterior restorations. ?Size?Small and large, large for adults, small for children.It works great for home teeth care, teeth whitening, Dental Office, Examination of Oral, teeth, tongue, pharynx, Tonsil Stones and so on. ?7 Parts?The product has seven parts, retractor, flexible connector, tongue guard, connecting arm, suction tubing, position block, and Y-connector. ?Adjustable Dental Appliance?Combined into each appliance is an adjustable cheek retractor, saliva ejector, tongue guard and low-volume suction connection.