The E Series product range is made from impact resistant polycarbonate and is suitable for use in a variety of environments and applications. Whilst they are not essential, the use of security screws (product code 31J) is recommended where additional peace of mind is required. 31J security screws are designed to be installed on the reverse of all E Series switches. The addition of 2 x security screws per switch prevent the switch mechanism from being dislodged after installation.