Elk TRG2440 24VAC, 40 VA AC Transformer with PTC Fuse Input Voltage: 120 VAC, 60Hz, .43A, Output Voltage: 24 Volts A.C. Auto-Resetting (PTC) Fused Secondary Green Power On LED, Grounding Prong & Terminal Electrical outlet mounting tab H = 4.14-Inch, W=2.74-Inch, D = 2.2-Inch.