Similar to the single version, but with two tubes to post the balls into. The balls trundle down the tubes in different directions and speeds, eventually dropping into the tray at the bottom.
Available in single and double sided versions.
With the single sided version, the balls are posted and exit on the same side, so you can be in one postition while using it.
With the double sided version the balls are posted on one side and exit on the opposite face, encouraging understanding of object permanence, social interaction, use of motor skills, etc