The E56 is available with threaded or flanged connections in 2″, 2-1/2″, and 3″ sizes. The E56 is available with a variety of factory set pressures ranging from 15-125 psi. The available spring ranges depend on the spring installed: 15-50 psi, 40-60 psi, 50-110 psi, or 80-125 psi.