The part number 6500-343 refers to the Theramax dual-speed spa pump, a 2.5 HP, 230V component used extensively as original equipment in Sundance Spas and Jacuzzi Hot Tubs.
This pump is a 48-frame, baseless model typically used as the primary jet pump in high-performance spa series.
Hot Tub Models and Brands Using the 6500-343
Sundance and Jacuzzi are the primary manufacturers utilizing this part, often across multiple decades of production.
Sundance Spas:
850/750 Series (1997–2004): Altamar, Austin, Cameo, Capri, Optima, and Maxxus (as Pump 1).
780 Series (2007–07/2010): Camden, Certa, Hamilton, Hartford, and Hawthorne.
680 Series (2008–07/2010): Burlington.
Additional Models: Bahia (2002–2006), Calypso (1997–1999), Caprio ST (2001–2003), Cayman (2003–2006), Cyprus (2000–2002), and Palermo (2002–2005).