Tender’s fish whistles are lost wax cast in England in two pieces, from solid brass. They can be blown through the mouth and sound through the left gills. They are fitted onto a brass-plated steel keyring, and the Plautus face logo is engraved into the belly.

To produce this whistle, Tender’s jeweller created the master with hand tools, from modelling wax. This needs to be in two parts, the head and air pipe at the front and the body at the back. This is so that a space can be sealed inside to allow the air to return on itself and sound a note. These master sections are then used to make a mould, into which wax is poured. The waxes of each section are packed in plaster, and molten brass is run in, melting away the wax and hardening inside the plaster. The plaster is then broken away and the pieces are filed and cleaned up.

The final joining of the two sections is done by the jeweler who made the original model. This is done with silver solder, which seals any gaps in the joint, and runs over slightly down the sides of the whistle. Any excess is removed, but the traces of silver and heat leave inconsistencies in the colour and patina of the whistle, which make every piece unique.