Factory Test: Numerous loading tests have been done showing our stool’s static load can reach 570lbs at most and dynamic load up to 400lbs. You can see how sturdy it is. Self-open Prevention: Self-open prevention mechanism is designed to prevent the foldable stool opening by itself when it is closed. This makes it more convenient and easier to bring it along for outdoor activities. Please try to avoid tilting the stool. Although the sidewall is reinforced make it have some capacity of resistance to tilt.