To be used with an ET Tube when the patient has 'Teeth Clench'.
The mouth opening is designed of spiral, it is moving in a spiral to avoid injuring patients teeth and the oral soft tissue, when patients jaw locked closed at stake or before anesthesia resuscitation.
The sufficient hardness of the mouth opening confront with the teeth of the upper and lower jaw.
It is made of less density polyethylene and accord with GB/T16886. 1 biology evaluating requirement.