Boost Module: With -USB voltage input, you can 9V 12V 18V 24V voltage by simply connecting the USB power adapter. Note: This is a boost converter module, so the output voltage should be at least 2V higher than the input voltage!Adjustable voltage: The power setting module has DC 2-24V input and 5V-28V adjustable voltage output, and the power conversion efficiency is as high as 93%. time a new voltage is passed, it will remain at the original voltage you set, will not automatically reset, and will not bother you to adjust each time.Widely used: These boost boost converter modules can be used to fix emergency lights, electronic equipment, DIY a mobile power supply with adjustable output, boost chargers, etc. Widely used in batteries, power , DIY adjustable regulated power supplies, industrial equipment, 5V, 9V, 12V, 28V output, etc.Note: The maximum output current is 2A. rotate 15 clockwise use. This is the direction to increase the voltage. When it reaches of the stroke, it will start to make a clicking sound. Then you can turn it down to the voltage you .Colour: blueMaterial: plasticPackage Contents:5 x Boost converter with -USBOnly the above package content, other products are not included.Note: Light 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.