1 Year Limited Warranty is ONLY offered on HID bulbs, ballasts, and igniters (not required if igniter is built into bulb or ballast) purchased together on one sales transaction (either in kit form or individual skus). Proof of all items purchased together on one receipt is required for warranty purposes. New bulbs, ballasts and igniters (not required if igniter is built into bulb or ballast) purchased together must be replaced /installed together in order for the items to qualify for warranty, otherwise these items are sold without any warranties.
As the items degrade over time, their performance will change. It is important that ballasts and bulbs stay balanced to work well together. Older parts are likely to cause newer parts to fail prematurely.