Accrding to A Druid Fellowship, the largest Neopagan Druid Organizqtion in the English-speaking world, this sign uses motifs from folk art depictions of the 'tree of life' to express core IndoEuropean Pagan concepts.
The Wheel is the sign of the Sky Powers, the turning, eternal order of the heavens. It is the sign of many sky gods, of the Thunders, and of the Sun, Moon and Stars.
The Hall of Lugh is the pattern of the Great Hall of the Gods, the symbol of the quartering of the world, of the establishment of the Middle World.
The Spiral is the sign of the Underworld Powers, the flowing, unshaped potential of all beings. It is the sign of the goddesses of waters, of the whirlpool, of the depths.
Together, these signs affirm the Order of the Worlds, a protection from ill and an affirmation of blessing.