I put one on my elec fuel pump and put the switch in the glove box. Worked wonders.
The one in my honda (before I sold it) had a momentary on and a solenoid. To start it, you had to push the momentary on button to get her going. Then I ran my solenoid (open under power) off the oil pressure idiot light. The fuel pump was on only when there was oil pressure. If you turned the car off, you could not start it without finding and pushing the button. I did this because a friend had a kill switch and his car was stolen ont he one night he forgot to flip the switch open when he got out.