1、DURABLE CONSTRUCTION: Designed with carbon steel and rubber, our dust caps are zinc plated for added durability. Resistant to deformation and rust, they can provide long term service to your trailer. 2、OPTIMUM PROTECTION: These caps are specifically designed to prevent dust from contaminating the trailer axles, preserve grease, protect the axle from damage, and offer decorative appeal. 3、EXTRA PLUGS: You'll receive 4 trailer axle caps and 8 extra rubber plugs, sufficient for your everyday use or replacement. The additional rubber plugs can also serve as emergency spares, adding value to this set. 4、EASY INSTALLATION: Featuring 8 detachable rubber plugs, the wheel hub grease caps are designed for easy installation and maintenance. Installation can be a breeze, even for beginners, and regular upkeep is a cinch. 5、PERFECT FIT: These dust caps are designed to provide a secure fit, effectively sealing the bearings and preventing any contaminants from entering. For boats, trailers, campers, RVs. Item Type: Trailer Hub Bearing Dust Caps Material: Carbon steel + rubber Application: Suitable for Boat Trailers Campers RVs 4 x Trailers Dust Caps 8 x Rubber Plugs