Is this a correct horn for my 1923 model T?

[36 conv sedan]

A friend of mine tells me my horn might not be correct... but I want to ask the experts. It does look different to what Macs has on their catalog as a Model T electric horn, but I have seen some at ebay that would seem to indicate mine may be correct... so, can anybody tell me if what I have is correct or not and if not, what model should I be looking for?

My car is a late 1922 or early 1923 touring.

Thanks!
Victor