Eternity because the three arms seem to resemble the eternal circle of birth, death and rebirth; balance bacause a second interpretation associates them to the elements: earth, water and sky are joined and integrated into each other.
In this triskell stylization S and G are the headletters of the names of Luca´s children whilst the letters I and L represent the names of Luca and of his wife, joining and embracing their children´s ones.