Stainless Steel replacement dust caps for boat or utility trailers using the E-Z Lube or Accu-Lube Greasing system. This dust cap is used if your axle is an axle with a grease fitting on the tip of the spindle. Rubber plug easily removes to access your grease fitting this dust cap measures 1.98 inches across and will fit most 4 and 5 bolt trailer hubs. Drive in installation ensures a tight fitment in your hub.