MAXIMUM AMOUNT OF BOXES PER ORDER IS 5 BOXES. Each box contains 20 SolarEdge S440 Optimizers, designed to maximize the power output of your solar panels. With a maximum input power of 440W and a voltage of 60V. The connector type is MC4. The SoladEdge S440 are S-series Optimizers, this series stands for Simple, Safe and Smart. These optimizers are very quick and easy installation.