This is the shortest conversation tube I have come across. It is made from a sprung metal coil which is lined in black silk. The tube can be bent to a suitable position and will then retains its shape and shows less flexibility that the longer examples.
The tube itself is tapered, being narrower at the earpiece end and this must have made its construction quite a challenge. The ‘mouthpiece’ is made from Vulcanite, the ear piece from the same or gutta percha.