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 5920-01-141-6885
NSN 5990-01-423-8189
NSN 5975-00-131-6811
NSN 2925-00-734-0516
NSN 5895-00-068-3778
NSN 5998-01-154-5315
NSN 6685-00-027-7186
NSN 5985-01-111-1578
NSN 4140-01-660-1317
NSN 6110-01-371-4616
NSN 5915-01-377-5881
NSN 6610-01-583-9635