The rigid rotor system thus eliminates the danger of mast bumping inherent in semirigid rotors. The majority of sialoendoscopes that are currently in use are of the semirigid type. Frameworks with connections of intermediate stiffness are commonly called semirigid frames. There are two primary types of penile prosthesis&colon; noninflatable semirigid devices, and inflatable devices. The semirigid rotor can also be referred to as a teetering or seesaw rotor.