Blueline Universal Elbow securely fits most park sewer openings without requiring additional adapters. Screws into 3 in., 3.5 in. and 4 in. male threaded openings as well as 3 in. female threaded openings. Pushes into non-threaded openings. Solid, one-piece construction prevents separation, providing a secure, leak-free connection. Provides a push-on connection to Blueline Ultimate Sewer Hoses. Also connects to standard sewer hoses.