Our Billet Aluminum Geared Hub Heat Sinks set (4) replaces the stock access cover plate of your geared hubs. Machined out of a solid piece of 1 Billet Aluminum, these heat sinks will cool the Geared Hub Oil, extending the life of the oil and bearings inside the Hub. A huge advantage when under heavy loads, towing or high performance applications. Available in your choice of anodized blue or black drain plugs. Custom power coating available upon request.