Tachometer Type E-4 Weston 545 A-20 Havoc H-21 but utilizes an electro-magnetic compensation

but utilizes an electro-magnetic compensation system

Weston model 301

The instrument would indicate the hydraulic pressure within the undercarriage system of the aircraft

labeled for engines #1 & #2 and 3 and #4

with an antenna wire connect from the top of mast to the top of the tail

Tachometer Type E-4 Weston 545 A-20 Havoc H-21 but utilizes an electro-magnetic compensationHere is a WW2 vintage electrical Tachometer measuring up to 3500 RPM. This is the type used on the Douglas A 20 Havoc attack bomber (see photo of instrument location on the A 20 cockpit panel as illustrated in its flight manual) as well as the C 45 Expeditor transport (both aircraft used 2 each). The anchor symbol of the US Navy appears on the rear of the instrument, so it may have been used in an aircraft of the US Navy. Measures 3. 25 inches