Low Voltage 300 Watt CONTRACTOR SERIES Transformer. Dimensions length = 13.0 inch, Width = 5.55 inch, Depth = 5.51 inch. Kichler''s Contractor Series provides the best options and flexibility needed for most installations. Output voltage will suit most jobs. Features include a commercial grade toroid core and coil submersible rating, pluggable timer and photocell outlets plus a 10 year warranty.