... 50Hz0.4232/50Detailed Product Description.Electromagnetic ballasts for metal halide lamp,sodium lamp,mercury lamp 35W,70W,125W,150W,250W,400W,600W,1000W,2000W ... high-pressure metal halide) discharge lamp; HM:(high-pressure mercury vapour) discharge lamp.1) Main voltage:220V-240V.2) Main frequency:50-60 Hz ... just feel free contact us, we will reply you within 24 hours. MH metal halide lamp 250w ballast