Discover the efficiency of the Aprilaire 8811 Protocol Adapter, designed specifically for Series 8870 Thermostats. This essential tool includes a 7.5VAC, 500MA power supply and effortlessly converts RS232 to RS485. It comes complete with a DB9 connector and cable, ensuring easy setup. Capable of supporting up to 32 communicating thermostats, the Aprilaire 8811 is ideal for any installer using a Windows-based computer or laptop to verify hardware and communications seamlessly. Upgrade your thermostat installation experience with this reliable adapter. Don't wait, enhance your system's capabilities today!