The King Electric King BKCB2BW K-Series 7-1/8" Dual Relay Control Box (relays not included) - Bright White falls under the K series. The K Series has the following features: Convection Heat, Quiet Running, Built-in Cable Clamps, Crushproof Element, All Aluminum Element Design, Full Length Safety Cutout, Baked Enamel Finish, Electro-Galvanized, Reinforced Cover, Soft Contoured Corners, All Knockouts are 7/8-Inch diameter, for .5 conduit, Removable Reflector and Optional 18-Gauge Front Cover.