A tray of Grodan 77 x1inch Rockwool (35x35x40mm) cubes for seedling and clone propagation.
Although it seems a little strange to place a square plug into a round hole (when inserting into a larger cube) ..this is for a good reason!
The outer edges of the square Grodan SBS cube will sit neatly on the top of the opening of a larger cube, which allows for an air-gap between the base of the SBS cube and the bottom of a larger cube..therefore reducing the chance of root damage whilst transplanting!!
For use with our 3" & 4" Large hole cubes or any other growing medium.