Spa Guts Replacement Balboa circuit board for the VS501Z spa controller model. Chip Number VS501ZR2D. OEM part number for circuit board is 54357-03. Board Features: Pump 1 dual speed, Blower/Pump 2 single speed, Ozone, Circa Pump. Circuit Board dimension (Approx.): 11 inch x 5 inch. This circuit board is compatible with the following Balboa Topside Panels: 52144, 51676, 51223, 51248, 54094. This circuit board is also the replacement option for the following Balboa Circuit Boards or Systems (NOTE: If using as a replacement board for a Viking Spa or other Spas, make sure the pumps are rated NO MORE than 230V 12A): 54585 (System), 55191, 55035-01 (System), 55036-01 (Chip VS240RR2C), 55228, 53268, 53267 (System), 55371, Chip VS501ZR1B, Chip VS501ZR2B, Chip VS501ZR2C, Chip VS501ZR2D, 54356 (System), 54293-02 (SYSTEM MAAX 167 VS501Z), 54294-01 (BOARD MAAX 167 VS501Z), Chip 167R1B, 56075-02 (SYSTEM MAAX 171 MXVS501Z), 59-138-1683, 3-60-0081, 33-0032B-K, 33-0032B, 54379-03 (System), 55191 or INFI07R1A (Verify Topside Panel for Compatibility), 55405 (MS520, X801125), 56926. This item comes with a 1-year limited warranty.