A plain planter with a 10 mm grove along the top edge.
This planter may be manufactured in various sizes from:
760mm x 760mm sq (avgerage weight 380 Kgs)
600mm x 600mm sq (average weight 216kg)
915mm h X 1.300mm l X 760mm d (average weight 600 Kgs)
This minimalistic planter can also be made as a cistern up to 1.7 meters in length.