Features: 1.Application: The bumper plug cap fits for most standard 4in square bumpers, and will conceal sewer hoses while allows air flow for veltilation. 2.Function: Cap has square hole in middle for air venting and to use for removing plug, this style bumper plug is used often on RV and trailers. 3.Unique Design: The design of the square hole in the middle of the sqaure bumper cap is easy to install and remove, makes it practical in use and function. 4.Durable Material: Made of high strength ABS plastic material, which is impact resistant, wear proof, anti aging, deformation proof and durable. 5.Fine Workmanship: Professional manufactured, exquisite workmanship with unique design, ensure stable performance and high reliability. Specification: Item Type: RV Bumper Plug Cap Material: ABS Function: Conceal the sewage hose while the square hole in the middle still allows ventilation Design: The design of the square hole in the middle is easy to install and remove Fitment: Fits for RVs, campervans, trailers, 4in square bumpers