Reference usaf dwg 56b23624, for special markings
A tachometer that is driven through the media of a mechanical connection and includes provisions for fixed mounting.
NSN 5920-01-206-9947
NSN 6685-01-499-1995
NSN 5945-01-580-5731
NSN 6320-01-498-4954
NSN 7035-00-549-2722
NSN 6145-01-597-8005
NSN 4140-01-425-1725
NSN 7035-01-008-5569
NSN 5930-00-716-4598
NSN 5950-00-517-0467
NSN 6610-00-614-7943
NSN 5910-01-245-3581