BMH Magnetic Ballast for HID Lamp Description For Metal Halide low wattage such as MHN-TD, CDM-TD, CDM-T, MH Using with ignitor SN 58 or SN 58 (T15) Working Temp. 130'C Dimension L: 117 x W:57.1 x H: 51.5 mm. Safety Features With Thermal Switch (TS) to cut circuit when temperature is high