It is made from vitreous enamel fused onto sheet steel.  Heavy gauge.  Very durable.

A very early example.  From around 1900.  A good example of industrial art that just can't be faked.

Convex (domed).  White enamel in relief - excellent definition.

6¼" high 7⅞" wide.

This is the real thing from a real house in real France.  Not a copy, not made yesterday.  From a property in Bondy, a Paris suburb.

Around four thousand house numbers in stock at the last count - large, small, old, high, low, enamel, cast metal, bell metal, convex, flat, Danish, French, Australian, Japanese, German, Belgian, UK.  Please let me know if this is not the number or style you require. But I have few numbers higher than #600.

UK shipping £3.  Elsewhere £14 tracked.

Please see my other listings if you like French signs and numbers.