The following kit is a "bolt for bolt" replacement for the standard alternator on the XP25 and M35 diesel engines. The kit features a Series 23 Powerline alternator with a 2" foot, 10mm bolt hole and 7.1" bolt to bolt layout. The kit includes an Aqualine Plus smart three step regulator with Bulk, Absorption, and Float modes, turn-on delay to protect belts, stepped voltage at turn on, GEL battery protection, Halogen light protection, and many other features that are intended to optimize charging of expensive batteries. The kit includes a wiring harness and instructions. The aternator does not include the pulley and must be purchased seperatly to meet your specific belt drive criteria.