Sigillo Solar Defender, for 6 mm hole. MARSS patented system for fixing the optical Fibre, installed as a _close ring_ between the panels. The use of the Sigillo Solar Defender to applie at the 6 mm hole existing on the panel frame, reduce of the 70% the installation time of the Fibre, allows the right install and to avoid too sharp curves that may cause undesired operation, increases the level of system security and preserves the panel guarantee.