UPuper Rockwool 4x4x4 Case of 144UPuper 4 inch Rockwool cubes are a good size for transition planting (transplant) or finishing small plants, and they feature a standard size rockwool pre cut (planting) hole for easy (easily) transplanting of seedling starts. They can effectively retain moisture, and their unique 4 inch size provides the minimum processing capacity for optimal activity. They are also very suitable for storing water or additional nutrient solutions required for root