The sensor must be carefully and precisely located on the outside of the housing in order to work. FIE include a couple of blueprints to show you exactly where to put it. You could always send your mag to FIE and them drill/tap the housing for an exact installation. We don't recommend customers drill and tap the mag themselves! To install it yourself, simply use a blob of silicone behind it and tape it in place just until the silicone cures.
The sensor requires 12VDC input (9 to 18V is just fine). Comes with a mating 3' long harness to complete the wiring task. This device creates TWO pulses per crankshaft revolution, so you'll set your RPM accessory to "4 Cylinder" input signal.