Stethoscopes require little maintenance apart from replacement of lost, cracked, or broken parts, such as ear-pieces and diaphragms (Fig. 3.3). On the older types, the tubing may perish and need replacing. While it is possible to buy proper, but expensive, stethoscope tubing, ordinary tubing of a suitable size may be fitted. Most newer stethoscopes have tubing that does not perish, though it can become sticky if certain chemicals come into contact with it.