Section 888.4600 - Protractor for clinical use(a)Identification. A protractor for clinical use is a device intended for use in measuring the angles of bones, such as on x-rays or in surgery.(b)Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter, subject to the limitations in § 888.9 .52 FR 33702, Sept. 4, 1987, as amended at 66 FR 38815 , July 25, 2001