I purchased this sign at an estate sale. This is the second of two signs he had. I was told that this was an original switch railroad sign that may have been a spring switch sign. I am not sure of the railroad company that this sign was from. It is a heavy porcelain and measures 9" in diameter. The person that I bought it from said he thought it was from the 1920s or 1930s. As you can see, the sign has a red "S", white on both sides, with the white being edged in black. The back is solid red. The porcelain has minor chipping around the 2 pre-drilled holes at the top and bottom. This is a beautiful sign.