Grodan Rockwool Wrapped Blocks 4"/100mm Cubes Small Hole.
These are used for transplanting. Once roots have emerged from the small cubes they are then usually placed in these larger cubes and then onto any system. Ideal for all types of hydroponic growing, this quality product offers you ideal air/water balance, simple controllability of water and nutrients and strong root growth throughout the entire block. Compatible with SBS77 (38mm) starter cubes. Dimensions: 100mm x 100mm x 65mm. Supplied in 6 cube rows.