Riedel Horn Decanter.

Inspired by the insignia which symbolises the Austrian Post's 18th and 19th century mail delivery system, the horn was apparently blown in order to signify that post had arrived, this "postal horn" influenced many musicians of the time, such as Mozart, who incorporated the horn into music which he composed.

This hand blown decanter is, rather unusually, designed to both be a decanter, and, from the smaller opening, be blown to simulate the postal horns of old.

Quite why you would want to play a tune on your wine decanter is beyond us, however, the product exists, and is on sale now for £675 per edition.