2C - 2 Circuit option 2 electronic ballasts for separate switching of lamps to allow dual level operation. Available on all Portfolio two lamp compact fluorescent housings. 2CMS - 2 Circuit Master Satellite option, two fixtures shipped together and connected with a 10' flexible cable setup for dual level switching. "Master" fixture has two 2-lamp electronic ballasts, each connected to a single lamp in each fixture, the "Satellite" fixture has no ballasts. Both circuits are only run to "Master" fixture to allow faster wiring.