This incandescent black phenolic socket is for use with medium base bulbs. It is rated for a maximum of 660 watts and 250 volts. The socket is UL listed and features a side mount with 9-inch leads. Precision Lighting and Transformer adheres to the strictest quality control and quality assurance procedures in the ballast and lamp industry. This Precision Lighting product is tested under the toughest conditions and meticulously factory checked for defects in materials to reach you in perfect condition.