An empty big bag.
An empty big bag which can hold a tonne of sand, gravel or chips. Bought on its own as an empty bag.
Blocks
A much bigger block with a cavity/hole going through the center.
Quarry Products
2" clean medium sized stone
Gravel
Aggregate mix
Drainage stone-small smooth rounded stone
Plastering sand
Chips
4" clean large stone
Regular 4" block with a 30 degree offset.
Regular sized blocks used for most building jobs.