For the intermediate stage between starter cubes and the final transfer of the plant to the growing system.
Always wait until the roots are coming out of the Rockwool before transferring a (small or large) cube into the next stage.
Rockwool products come wrapped in plastic. This makes the medium easier to work with but should be removed after soaking.
Small Hole (SH) are 1" in diameter.Large Hole (LH) are 1" in diameter.