Genuine FSP ATX-300GU (NOT A SUBSTITUTE) 300W Power Supply for Bestec ATX-250-12V Power Supply Replacement ATX-300GU 300W Power Supply for Bestec ATX-250-12V Output: 300 Watt Power input: Use switch to change between 115/230V Dimensions: 5.9" x 3.4" x 5.5" (WxHxD)