Edelbrock Inductive RPM Sensor (Part Number 71937), designed to generate a tachometer signal without splicing into existing wiring. 

Compatibility: Works with carbureted and most Electronic Fuel Injection (EFI) engines.

Function: Clamps onto a current-carrying wire (like a coil primary lead) to provide a stable 12-volt square wave signal for tachometers or shift lights.

Installation: Features a no-splice, no-cut installation for quick setup.

MSD Tach Signal GMR Pickup

Clip to a coil pack primary lead to produce a stable 12-volt square wave for a tach, shift light or RPM-activated accessory. Specs...

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