1.The input voltage of the product should be the output voltage, and it is best to maintain a voltage difference of 1V or more. The input should not be reversed, but connected to a reverse burning board. 2.It is best to disconnect the power supply when wiring, otherwise when the voltage is high, it is easy to spark, which may pose a certain risk of chip damage and breakdown. 3.The wiring should not be too thin to that the wires can withstand the corresponding current.Protect the inductive load to avoid excessive reverse electromotive force exceeding the chip's bearing range. The higher the power used by the module, the closer the current is to the maximum current. The heat increase, so pay attention to heat dissipation when using. 4.When there is no external heat dissipation, it is recommended to keep the current below 4.55A for continuous use. If it exceeds 4.5A, additional heat dissipation is required, otherwise it overheat and protect the output. 5.It is recommended to use a voltage below 26V. If the supply voltage is not very stable and the voltage exceeds 27V, it trigger the internal overvoltage protection of the chip. To stable operation, leave some margin appropriately. Module interface:VIN+: DC input positive pole 6V-27V (needs to be 1V higher than the output). GND: DC input negative pole, connected to the output negative pole. +(OUT+): DC output positive pole. -(GND): DC output negative pole, connected to the input negative pole. Specification: 9V Due to different batches, there may be differences in product appearance and printed text, which not affect use Colour:As Shown Material:PCB+Plastic+Metal Package Contents: 1 x Antihypertensive board 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.