Gramophone sound-boxes have a mica or metal diaphragm supported around the edge. In most sound-boxes thin rubber tubing is used as the support and as rubber tends to perish and become harder with age, the gaskets need to be replaced from time to time.

The tubing used nowadays tends to be made from a modern flexible plastic and about 35cm is usually sufficient to make the two gasket rings.

Price for 35cm is £6 including postage within the UK