Lay flat size of the bags is 18″ x 4″ x 29″. These bags are filled with HRock/clay soil/cement and tamped in 3 stages on filling.
The foundation bags are cement stabilized. Double bagged. The rest of the bags are filled with lime road base or clay based soil.
Finished size of the bags are about 14″ x 7″ x 21″.
Three places you can use to check levels: (besides the water level demonstrated later)
Long level on far side for horizontal, yellow one the compass arm and short torpedo level just behind the tamper.
The bag holder is a tomato cage and works very well.