The style of these instruments is unlike the few extant "butter-stamp" telephones offered in recent years. Most are in mahogany although boxwood examples are also known. The carving is also unusual as the norm was for minimual, if any, decoration.

The earpiece on one of the four is diffrent from the others, with Gothic-style carving. This suggests that others existed in the set.

The size and style suggest a Continental origin, possibly for use with the Theatrephone or similar early broadcasting device. Another possibility is that they were commisioned for a palatcial building.

There is an un-substantiated traditon that they were originally in Windsor Castle.