An empty small bag.
An empty small bag which can be filled with 4 stone weight 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.
Concrete block that weighs one tonne.
Chips
3/8" Chips. Very small stones
Bags
Small empty heavy duty sand bag.
An empty big bag.
Gravel
Clause 804
Quarry Products
2" clean medium sized stone
Drainage stone-small smooth rounded stone
Regular sized blocks used for most building jobs.