The card of the printed circuit board is made of plastic or fibreglass this is usefull as both these materials are not conductive. Conductive materials, like copper, are etched in thin lines in between the layers or on top of the circuit board making the electricity flow only where it's required.www.engineersgarage.com
A plastic casing protects the bulb from damage. It can easily be removed in order to change the bulb.
A screw prevents the plastic casing from coming off, however it is easily removed with a screwdriver to allow the bulb to be changed.
This part of the lamp is plugged into the mains, however having a French/German plug it is directed at users in those countries.lacolorpros.com
I think that the lamp is made of low density polythene as it is tough (this makes the lamp durable) and and an electrical insulator.