Grodan A'OK plugs are designed for seed and cutting propagation prior to "blocking on" into larger growing blocks
Grodan Stonewool (rockwool) is made from molten rock spun into cotton candy-like fibers.
The purpose is to support the requirement of the plant in the different plant stages.
Made of molten rock spun into cotton candy-like fibers and then compressed into cubes, blocks, or slabs.
The V-shape design of the plug discourages tangling of roots.