U.S. Code of Federal Regulations
Regulations most recently checked for updates: Aug 28, 2025
(a) Identification. The toynbee diagnostic tube is a listening device intended to determine the degree of openness of the eustachian tube.
(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 § 874.9.