Brass effect resin grid base with central pentagram surrounded by 5 shallow dishes at the end of each point. These dishes would be brilliant for orbs, but you could try crystal chips or tumbles as well.
 
The 5 pointed star (known as a Pentagram) is associated with the elements of Earth, Air, Fire, Water and Spirit.
 
When the 5 pointed star is surrounded by a circle it is known as a Pentacle. This grid is a variation on a Pentacle, but would still be perfect for a protection grid.