This 400 amp alternator, part of the Elite series, offers high amperage output and durability. It features 6 phase technology, twin rectifier assemblies, and 12 large diodes for daily use reliability. Producing over 200 amps at idle and 400+ amps at cruising speeds, it comes with a smaller pulley requiring a slightly shorter belt. Installation may need an adapter harness for vehicles with the CS144 Heavy duty charging option. It's a direct plug-in for trucks with an oval shaped 4 pin plug. Fitment includes various GM trucks, vans, and SUVs from 1996 to 2007.