Kichler 15PR600SS Pro Series Transformer 600W, Stainless Steel 19 in H x 6.75 in W x 5.75 in L A toroid core saves energy and is 10% more efficient then an El-type core, and runs cooler and quieter (no hum), and runs smoother (no vibration) Stainless Steel finish Constructed of Stainless Steel Tilted terminal board and large size lugs inside the taps hold up to eight 10-gauge wires or up to ten 12-gauge wires per tap and one photocell outlet