4" Site Sewer Cap   Select Image for Closer Viewing     A 4" Site Sewer Cap made of casted metal, designed for waste disposal of campers and travel trailers at individual RV sites. Can be locked to control dumping without your permission. Industrial yellow. Not to be used at RV dump stations. The Tower Company, Inc. P.O. Box 1958 Manitowoc, WI 54221-1958 1-800-945-1532 or 1-(920) 682-6091 Fax: 1(920) 682-6094