These systems are the perfect choice when building a bike from scratch or when upgrading your weaker charging system, the alternator rotors feature fully encased sets of magnets that have no way of working loose like OEM rotors are known to do . Instead of having just six long magnets like OEM rotors, these rotors have 12 short magnets to match the number of laminated windings found on the stators, our part number 17850, includes our 17829, performance alternator rotor, All systems include a chrome plated Regulator/rectifier . V-FACTOR . Mpn: 17850 . Item Weight: 8 .16 lbs .