They are made of steel and are listed as having no surface treatment (no coating or finish).
They use a patented “Easy-off” release mechanism with a lever that snaps onto steel and disengages quickly, so you can lift the lever and move the cup holder or basket to a new location repeatedly.
Each item is listed with a 1 Year Limited Warranty in the product details.
Product details commonly list capacities of 25 lb and 35 lb, specified for use on thin steel surfaces.
They attach to many common steel surfaces, including toolboxes, storage cabinets, refrigerators and freezers, steel doors, workbenches, washers and dryers, lockers, steel vehicles and tailgates, and carts.