F-can ballasts are needed for limiting the draw of current so that the circut elements will not burn out. Ballasts stabalize the current that is drawn. Hence, properly maintaining the safety and life of your HID lamps.  

All ballast kits contain the appropriate core and coil ballast, prewired to the correct rated dry capacitor and internal resistor and include starters where necessary. Kits are individually packaged in corrugated cartons and include seperate adjustable mounting brackets.