The SunBlaster Connector Cord is for growers who want to add even more SunBlaster T5 tubes to their lighting system. These cables link tubes together, end-to-end, saving power. They enable up to eight ballasts to be connected together, with only one wall plug. Please note that this product is an "extra" cord. Each SunBlaster Fluorescent Grow Light includes both a power cord and one Connector Cord.