100% New. This 200 Amp SR Performance Alternator is 100% brand new, not re-manufactured like other companies sell and it has been fully tested at the time of assembly. This SR Performance Alternator comes complete with an internal voltage regulator and pulley. This 200 Amp alternator will greatly increase the charging capacity of your 2005-2008 GT Mustang with no modifications required.More Power. The SR Performance 200 Amp Alternator produces 100+ amps at an idle (2000 alternator shaft RPM) and 200+ amps at maximum (6000 alternator shaft RPM). Designed for highly (electrically) modified cars - this alternator will significantly increase the charging capacity at all RPM Ranges with no modifications when upgrading from smaller units.Peace of Mind. Why waste your time and money rebuilding your alternator again and again when it will only fail? Replace your faulty alternator with a brand new high performance one from SR Performance for peace of mind.Required Upgrade. In order to properly use this 200 Amp Alternator, you are required to upgrade to a Premium Power 4 Gauge Wire Kit. This is because the OEM wire was not designed to carry the larger charging capacities of higher Amp alternators. See the Buy Together section above.Application. The SR Performance 6G Series 200 Amp Alternator is a direct fit replacement with no mounting bracket modifications required to be installed on 2005-2008 GT Mustang models. The stock belt can be used on original equipment vehicles.