Product Details: Update your semi truck with enhanced roller support, with the NTN 4 1/4" Alloy Steel Tapered Roller Bearing Cup that ensures you're Ready for the Road Ahead™. With a sturdy design, this replacement cup works to house a bearing system that reduces mechanical friction between rotating components. Crafted with case-carburized steel for long-term reliability. FleetPride is your First Click in Heavy Duty®.