Solid state rectifier, positive & negative applications. Replaces the lucas finned rectifier fitted to many British bikes from the early 1950's to the late 1970's & will suit all 6V/12V models fitted with an alternator except the later electric start Triumphs & Nortons. Earth (Pos/ Neg): Both Voltage: Both 6v & 12v Single Phase: Yes OEM: 99-9882