Improve Efficiency - Solar optimizers are mainly used to optimize the output power of solar photovoltaic panels to ensure that the system can work at maximum efficiency. Solar optimizer can significantly increase system power generation by 5-25% Durability and Compatibility - Photovoltaic optimizer is made of high-quality material, which is wear-resistant, durable and corrosion-resistant and Almost Compatible other brands of photovoltaic panels. Simple Installation - Just connect the input end of the solar panel optimizer module to the output end of the photovoltaic module to convert the small current into a large current. The installation is convenient and simple. Note:If the appearance is slightly different, it will not affect the use. Colour:Black Material:Plastic Package Contents: 4 x MPPT Power Optimizer Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.