Our manufacturing process is what sets us apart from every other commercial playground supplier. All of our play ground equipment. and products are tested by National Testing Standards. We use stainless steel and carbon steel in all of our commercial & residential playground equipment. and swing sets, while others use only spring steel. If someone attempts to vandalize a spring steel seat its steel is exposed to the elements and will eventually rust and break, possibly causing an injury to a child who plays on this play ground equipment. Our stainless steel swing sets. do not have this problem making them more durable and eliminating a possible injury to a child.