Shown is a vintage General Electric Type IS-4 singe phase switchboard meter. I purchased this meter a few years ago and replaced the electromagnet as the potential coil was shorted out, possibly from a lightning strike or an accidental over-voltage. The electromagnet was a 120 volt, 5 amp type, identical to the type used in a GE type I-14 of the same specifications. I had a spare I-14 that lacked damper magnets and a register, so I used it's electromagnet to replace the one in the IS-4. Works great now! Although this meter is small, it does weight in at 15 lbs. All cast iron and well made.