The electro-magnet is under the dash. It has to be energized so it will attach to the engagement lever. the magnet is what actually moves the linkage to engage the pto. The safety system works with the seat switch. When you are in the seat, the seat switch closes and allows current to flow to the electro magnet. The magnet then is attracted to the lever and when the lever is engaged, the pto is engaged. If you get out of the seat while pto is engaged, power is shut off to the magnet and the pto stops. The lever will stay in engaged position due to a spring under dash. There is also a timer in the circuit. It provides a delay so if you bounce up in the seat momentarily(2 seconds), the pto stays engaged.