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.
Gravel
Clause 804
The bigger thicker blocks up from the 4"
Quarry Products
Plastering sand
Chips
3/8" Chips. Very small stones
Aggregate mix
Bags
An empty big bag.
Regular 4" block with a 30 degree offset.