Fitting an emergency telephone handset to the Car Operating Panel (COP) is a cost effective means of communicating between the person in the lift and a 3rd party outside of the building. Connection to a telephone line is required. Unlike an Autodialler, there is no control over which numbers are dialled. Therefore, conventional telephones are only suitable in an environment where the usage can be controlled (e.g. in the home). Standard emergency telephones are not suitable for public environments as there is nothing to stop someone ringing the speaking clock in Australia and then leaving the phone off of the hook – as you can imagine, the telephone bill would be exorbitant.