This is an aftermarket replacement spring kit, part number 9RK0003NO, designed to be compatible with ADR components. Identified as 'MUELLE Ø4.5L 133 KIT (4)', this non-OEM alternative includes four springs, each with an approximate diameter of 4.5mm and a length of 133mm. Ideal for maintenance or repair, this kit provides a cost-effective solution for replacing worn or damaged springs in various agricultural or industrial applications that utilize ADR axles or suspension systems. Ensure compatibility with your specific equipment before purchase. This product is a high-quality, non-original part offering reliable performance as a direct replacement.