K568220 Oil Cap For 10K - 16K Alko/Hayes Trailer Axles. These Oil Caps Are NOT Used On Dexter Trailer Axles Oil Cap For AL-KO 10K - 16K Trailer Axles Outside Thread Diameter: 3.75" Includes (1) Oil Cap, (1) O-Ring & (1) Rubber Plug Cross References: K568220, 420-K568220, K568220PTP, K71-859-00, K7185900, K71859, K71-859, Q-10-14k-PCAP