This is an on board glow plug igniter. Usually with a nitro you have to carry a tool that looks like a screwdriver. It fits over the glow plug and heats it up red hot, and then you turn the motor over with a pull start or roto starter to start it. The Savage has a roto start with is just a shaft style starter that fits into a motor plate that's connected to the crankshaft. When the shaft spins, the motor starts. The Traxxas has an Easy Start, which is similar to a starter on a car. there's a small electric starter motor connected to the backplate of the motor, and you hold a wand in your hand with a battery in it and control board. There's also a wire running to the glow plug. WHen you plug the hand wand into the plug on the truck, the battery heats the glow plug and the control board tells the electric starter to spin when you push the button.