Has high quality as the rubber wheels are made by one of the most knowledge and biggest rubber wheel manufacturer of Vietnam. The rubber is very well-made: cushion and durable. In normal cases, they are said to be used for 2 - 3 years continuously.
Extra heavy duty type: painted coating & tapered bearing. The steel bracket bears high load and promising smooth operation. However combining with rubber wheel, this strong bracket is just showing 50 - 75% of its ability.