We use three of these plants Roller our tomatoes on the balcony for window cleaning to push to the side, or to those to be repositioned slightly depending on the sun. Whether the stated maximum load is permanently endured, I put time in question, there is finally timber in which the rollers are mounted. But for 20 kg, it is sufficient slack in any case. If you like, the untreated wood for outdoor use and for better cleaning even with boat lacquer (clearcoat) paint or overspray. For the price of the item is definitely in order!