Description: This stainless steel 230V. heater body (housing) is rectangular shaped and has three intake/discharge ports. The two 3/4″ ports, located on the end and side of the heater body, are used to circulate water through the housing via a small circulation pump. The smaller 1/4″ port is used to drain the spa heater when winterizing the spa (draining it for the winter). This housing holds two 230V. heater elements (NOT INCLUDED).