A fine interwoven wire style that offers smaller gaps compared to other security grilles, mesh grilles include a restrictive style of security to an opening. It is a good choice when you need to prevent access from objects or hands from passing through an area that needs protecting.
When installed externally, mesh offers a level of protection to prevent smashing of glass using medium sized objects. When installed internally the common purpose is to prevent access for operating locks on doors or windows. Both internal or external installation also offers a reasonably good level of generally preventing unwanted access.