TACHOMETER
SHD30-40 digital tachometer and hourmeter by Murphy.
Panel-mounting design
Plastic enclosure (5-1/16 (129 mm) long 4-1/4 in. (108 mm) high)
Back plate with studs to mount like a SHD-45, OPLFC
RPM data and power supplied by magnetic pickup or capacitor discharge (CD) ignition
3 to 666 Hz ignition frequency range:
1 to 10 kHz magnetic pickup frequency range
0 to 65535 hours hourmeter range