Grundfos 1/25hp PVC Circ Pmp 120V 10gpmPump, 570 gph, 120V Grundfos makes only this pump for the spa industry. It has a 1" barbed fitting which most Sundance used a glue in or 3/4" barbed fitting. You must adapt the plumbing to work on the spa or if your spa used a 3/4" barbed. you can use the 6500-038 Laing Pump, but would need to change positon of the base of the pump to adapt the plumbing. There is no straight across exchange out for the old pump. Cross Reference 242011400, 31842, 59896351, PMPUP1520S115V, PMPUP1538SPA