... -restart time interval of 5 Mintues; * UL standards;low cost * High Frequency sine-wave output, the lamp electrodes impact smaller , low lumen ... decay , free of flicker & noise , compared to low frequency square wave output ballast, lamp lifetime span last more than ... EN61000-3-3 EN55015 * Size : 76*69*32 mm 20W High Frequency Metal Halide Integrated Bulbs