The Piggy bead from Czech brand Preciosa Ornela is a round concave pressed glass bead that's 8mm in diameter and 3.5mm deep. It features a center hole and an second hole offset 3mm from the center. Because it is convave, this bead cups around ball beads well. It also creates an interesting nesting pattern when strung togehther with other Piggy beads. As a pressed and tumbled glass bead, these may vary in size, color and shape slightly.