This bottom roller is a durable undercarriage replacement part for your excavator. Our rollers utilize special high strength-hardened steel and quality seal groups that provide excellent lubricating oil retention. Sealed bearings stop dirt, mud, and grime from penetrating inner components.Made of durable material which is totally corrosion and dust resistant, each item has been factory tested and meets or exceeds OEM specifications. It was designed and manufactured to exact OEM specifications using a high-quality, high-strength steel. It will provide long-lasting and dependable performance even if you operate in the most extreme conditions.