【Compatible Models】42001-0107 transformer compatible with pentair mastertemp/max-e-therm heater transformer, compatible with pentair mastertemp or sta-rite pool and spa heater electrical systems. 【Dual Voltage Capability】The Pentair 42001-0107S supports 120/240 AC voltage input and provides a stable 26V AC output. Perfect for a variety of pool and spa heater electrical systems. 【New Upgrade】We have made improvements and upgraded designs to make the 42001-0107 transformer kit more stable and durable, to ensure that each product reaches the best performance and exceeds OEM standards. 【Easy Installation】42001-0107S transformer kit can be easily replaced without tools and works as expected. Always check the heater wires before unplugging the old wires so you can reconnect them correctly. 【After-sales】If you have any questions, please feel free to contact us via Amazon email, we will respond to you within 24 hours and help you solve the problem. 42001-0107 Transformer 120-240v Dual Voltage Transformer Kit, Fit for Pentair Mastertemp or Sta-rite Pool and Spa Heater Electrical Systems 42001-0107S