Abstract: The present invention generally relates to a retention system that could be used to install in the internal surface of face-shields (7), for example of motorcycle helmet's visors, several devices, like screens working as solar filters, anti-glare screens, antifog screens, anti-scratch screens or different types of screens or devices, without alter or modify the characteristics of the visor (10) on which they are applied. The screen and the visor itself are this way preserved from damages, alterations and/or early substitutions. Such a system is constituted by at least one screen (1) and at least one gasket (2) with adhesive characteristics that can make such screens removable and re-positionable. This system can be created exploiting the characteristics of some materials.

Abstract: The present invention generally relates to a screen 1 of the type including a visor 2 whit variable transparency as a function of the extent of the electrical values measurable at its power supply clips 3. The visor 2 is power supplied by a respective electric source with the possible interposition of appropriate devices 4 for the control and management of the electrical values of the power supplied. The liquid crystal visor 2 is flexible to be adapted to the surfaces of installation and the electrical power source includes at least a photovoltaic cell 5.