Tachometer, Mk V, US Navy 88-I-2500 Pre-WW2 thus changing its position with

thus changing its position with relation to the rest of the instrument

This example has the manual back-up ring-and-bead sight affixed to its housing

It received signals from two antennae (see photo) typically mounted on each side of the aircraft forward of the wing

part number 6531-1L-B

Its use was carried over to aircraft used in the Korean War

Tachometer, Mk V, US Navy 88-I-2500 Pre-WW2 thus changing its position withThis is an original WWII era electrical aircraft Tachometer, Mark V FSSC 88 I 2500, as used across aircraft of the US Navy, such as the SBD Dauntless Dive Bomber, TBM Avenger Torpedo Bomber, and F6F Hellcat Fighter. Pioneer Bendix part number 2222 IF2 A. Range 0 3500 RPM, with the pointer indicating RPM hundreds and the inset window at 9 o'clock indicating RPM thousands. This tachometer is in exceptional condition given its age. Measures 3. 25 inches