Furrion 25-Amp and 50-Amp MPPT Solar Charge Controller are designed for solar array of up to 300W and 600W respectively. They provide the optimal amperage, monitor and adjust the output from your panels to prevent harmful overcharging of your RV batteries.  The MPPT technology optimizes and converts your panels' output to provide maximum charge following the automatic multistage charging that switches modes as the battery charges, helping extend battery life. The controller automatically adjusts the temperature to compensate for temperature variations. The quiet cooling fan prevents overheating. Easily mount the controller onto a wall with the included wall mounting bracket.