If You have a Sepex Controller, Club Car Precedent or DS IQ, the main difference between a Speed Magnet (4-pole magnet) and the Dealer Speed code 4 is the reduction of Regen brake.
The speed magnet will eliminate a lot of the Regenerative brake that happens when you lift the foot of the pedal.
The speed magnet has the possibility to allow the cart to go faster than 19mph as long as the cart electronics and battery can go faster.
There are two different models of magnets depending if You have a GE or ADC motor, the links below will help you determine what you have, just click on both and look at the descriptions:
GE Motor: https://www.revolutiongolfcars.com/p...otor-iq-system
ADC Motor: https://www.revolutiongolfcars.com/p...otor-iq-system