This is what 6kg of Real reef rock looks like

Aquaforest Rock - 10Kg (Arch/ Base/ Shelf/ Mix ) — East Ocean Aquatic

Real Reef Rock (by weight per Kg)

Real Reef Rock - Mini Plate Corals Per Piece – Candy Corals

Real Reef Rock - Medium Rocks 45lb Box – Candy Corals

Coral Reef Eco-Friendly Rocks

Real Reef Rock Purple (per lb)

Tank 4, 6kg of live rock, Wayne Rowley

Walt Smith Farmed Fiji Living Stone

Real Reef Small/Medium 55 lb. Box