The Replacement Transformer for the Reef Capable w/ Timer 24"- 36" & Aquatic Plant w/ Timer 24"- 36". This Transformer will also work with the old style non-Timer units that have a pigtail. If your light is one where the transformer plugs into the fixture directly, this Transformer will NOT work. This transformer must plug into the pigtail (short wire) that is hard wired to the fixture.