Missing Yours?: These inputs are designed specifically for your ballasts, are brand new, and will adapt your ballasts for compatibility with all of our relay harnesses. Best of all? They're free... .when you buy a set of Denso ballasts from our shop that is! Power Up: It's difficult to power a set of Denso ballasts without these pigTail Lights due to their proprietary input connectors. With a specially molded output plug just for those ballasts, you'll be ready to rock n roll once you've got these in-hand.