Blocks
Regular 4" block with a 90 degree offset.
The bigger thicker blocks up from the 4"
Quarry Products
Drainage stone-small smooth rounded stone
Bags
Small empty heavy duty sand bag.
Plastering sand
A much bigger block with a cavity/hole going through the center.
A tonne bag of sand.
An empty small bag.
2" clean medium sized stone
Gravel
Clause 804