OPT7 2pc Bolt AC 35w Slim Replacement HID Power Ballast for Xenon Conversion Kits REPLACEMENT BALLASTS ONLY: Requires HID Bulbs (sold separately) to complete kit Bolt 35w SLIM Ballast: Super bright 3,300 Lm power, 30 % smaller than regular Bolt Series, no flickering with AC ADAPT technology, and a reliable waterproof aluminum case Easy to Use Plug-and Play with QuickSnap connectors. Can be used with any OPT7 AC Bulbs. Includes: Two (2) OPT7 Bolt AC 35w Slim HID Power Ballasts