Ballast needs to be added to the unit to make it Freestanding - we recommended filling the chamber with at least 40kg of sand for a single cat household.
The Worm Hole apertures in Shelves are set to the front of the unit to give a more private sleeping area to the back of the compartments - the unit comes swith a Twist Pile insert to place of a Worm Hole Shelf to turn it into a Full Shelf.
For more information please visit our SixToo™ page.