Dexter's Fortress Oil Cap provides revolutionary protection for your trailer axle. Engineered with precision, Fortress includes a durable Dexter genuine bolt-on and threaded bearing protection solution. Its reinforced retainer ring design offers a shielded clear viewing lens, safeguarding against damage. Built from cast aluminum and enhanced with a resilient black coating, the cap provides an additional layer of robust protection. A resilient rubber O-ring and gasket ensure airtight sealing for optimal performance. Featuring a larger, conveniently accessible side fill/drain plug, this innovative product streamlines maintenance tasks. Whether for oil or grease applications, the Fortress Oil Cap adapts to your needs. Backed by Dexter's 5-year warranty, it guarantees reliability and peace of mind. Upgrade your trailer with the Fortress Oil Cap and experience unparalleled convenience and performance.