These are exceptional quality and value.
I used to "lift" kitchen appliances (toaster oven, microwave etc) clear of benchtop for more benchtop space. Ideal height for thisbut not suited for a full row of overhead cuboards, but a real 'wow' factor.
Used these supports to make a simple bench with three lengths of 2x3s. Everything worked well, the steel is very stiff and stable, the mounts are well designed, and the weight is not excessive. These are a real bargain IMO.