Zinc plated replacement dust cap for boat or utility trailers with Accu-Lube or E-Z Lube Spindles. This dust cap is used if your axle is an axle with a grease fitting on the tip of the spindle. The Rubber plug easily removes to access your grease fitting this dust cap measures 1.98” across and will fit most 4 and 5 bolt trailer hubs. Drive in installation ensures a tight fitment in your hub. This style of dust cover or grease cap is common on both utility trailers and both trailers. This is the correct cap to select if you want to take advantage of the easy greasing maintenance the zirc fitting on the top of your axle provides.