1. Fits standard 4 inch square bumpers and will conceal sewer hoses. 2. Used on RV, Camper and Travel Trailer. 3. There is a square hole in middle of the end cap, which is for air venting and to use for removing plug. 4. More durable material, as well as being a more snug fit. These caps will last longer and won not fall out of the bumper end in transit. 5. Material: ABS
