The Gavita Slim Line 2 (SL2) fixture features the Intensity Optic Reflector, which produces incredibly high light output in a focused area. It?s designed to deliver high uniformity to give your plants ample coverage where they need it. The SL2 features highly efficient passive ballast cooling that helps contribute to long fixture life. Other features include sealed housing with a Gore-Tex? ventilation plug, and controllable output up to 1150 W. The SL2 is also equipped with a Repeater Bus interface. This double-port connection enables control of the SL2 with a Gavita EL Controller (sold separately). Connect up to 100 fixtures in a single daisy chain series, up to five daisy chains per EL controller output. A single EL controller output can control up to five 100-fixture daisy chains, giving you room to grow.