Eye nut in accordance with DIN 582 is a specific type of nut that has an eye-like shape on top. A4 refers to acid-resistant stainless steel, which is known for its corrosion resistance and durability, especially in humid and corrosive environments. Eye nuts are often used to fasten and lift heavy objects using hooks, wire, rope or other lifting equipment. Eye nuts are typically used in industry, the building and construction sector, maritime applications, etc.