Mfg. - MAGNETEKMfg. # - 413-C-TC-P5-1/8" x 1-7/8" x 1-3/8"For use with Lamp type:F40T12, F30T12, F40T12ES,F40T12CWX, F48, 25W/UTSL,Worklite 25.Auto Resetting Thermal Protector.