Hendrickson's HXL Extended-Life wheel-end system is designed to incorporate their patented Axle Filter and Vent System, which allows the wheel-end to vent through the axle instead of the hub cap, protecting the wheel-end from internal contamination. The semi-fluid grease is formulated to perform in demanding conditions of elevated temperatures and provides anti-wear and low friction performance, and is less prone to leaking compared to oil. the system also features a patented nut system that allows for ultra-precise bearing adjustment, and a non-vented aluminium hub cap to protect against ingress of contaminants in tough environments and during power washing.