Split Nuts Included – Genuine Part – Balboa # 58104, 58303, G7410The Balboa M7 Heater Assembly is developed with patented M7 technology for reliability and quality construction. It features a stainless steel housing and is front mounted for simple serviceability. Measuring 15″ length with 2″ x 2″ unions and it uses 4.0 KW for efficient and fast operation.58083 is the same heater except has a 5.5kw element.