The "1G" in the description refers to the fact that the pattress is designed to accommodate a single-gang electrical component, such as a single-gang switch or socket. The "16mm" designation indicates the depth of the pattress, which is 16mm. This measurement is important because it determines the amount of space that is available inside the pattress for wiring and other electrical components.
This particular pattress is suitable for a variety of electrical installations, including residential, commercial, and industrial applications. It is designed to be easy to install and is typically made from a durable and heat-resistant material, such as PVC or polycarbonate, that can withstand the rigors of daily use. The pattress is typically mounted directly onto a wall or other surface using screws or other fasteners, and is designed to provide a secure and stable mounting point for the electrical component. It is also designed to provide a degree of protection for the wiring and other electrical components that are housed inside.