in a polish language:
'Formo Ochronna: cztery razy cztery, Przebudź się w nas!'.
Almost burnt-out black candle,
... and remains of 3x black incense on red stick.
Symbolically, Black is color of Protection,
Numerologically, 4 is associated with passive protection - like square of four walls around castle.
4 tools / 3x incense + 1x candle / x 4 / symbol of protection / is 16.
1+6 is 7, numerologically all around protection, well-being, wealth, luck & happiness.
... is 7 also the symbol of love?
... i think there's no better candidate among numbers.
... in buddhism love is wish for one to be happy and to have cause of happiness.
This is a little of esoterics that should protect me, loved one & friends from harmful people's actions and from karmic return after using black magick / mostly curses /.