DuraTrax glow-starter is powered by replaceable alkaline D-size cells (not included), which offer more capacity than NiCds, and at a lower price. Unlike NiCds, alkaline batteries provide the convenience of not needing to be charged overnight before a day of racing. D-Cell is enclosed inside a high-impact black polystyrene case with an easy-access hatch for quick replacement. Proven Twist-and-Lock tip keeps the starter securely attached with spring-action strength, and allows for a more compact design. 1-1/2" long neck for deep cylinder heads Rubber protective tip cover to prevent shorting in the track bag.