The Tridonic PC 1x 4-13 W Basic (Square) is a non dimmable basic high frequency ballast to run: 1 x 4 Watt T5 Fluorescent tube OR 1 x 6 Watt T5 Fluorescent tube 1 x 9 Watt T5 Fluorescent tube 1 x 13 Watt T5 Fluorescent tube OR 1 x 10 Watt 2D compact fluorescent lamp.