A more advanced type of plug is the pre moulded variety, made from plastic these types of plug often contain features making them detectable by metal detectors and x-rays if they are lost during production. This makes the plug particularly useful in production involving consumable products such as food. These plugs come in a variety of colours and may also be attached together by a cord or bar which sits behind the head or in front of the chin ensuring that the individual plugs are not lost. Also some varieties of this type of plug are reusable making them highly cost effective.
These two types of plug may be suitable for working in noisy environments but when working with tools which vibrate heavily classic ear protectors are much more suitable. This type of protector consists of a headset with a band across the top of the head meaning that they are securely strapped in place.
The type of protection used depends on the type of job being carried out therefore you should ensure that the protection is suitable for the job.