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 to make a clicking sound. Then you can turn it down to the voltage you . Colour: blue Material: plastic Package Contents: 5 x Boost converter with -USB Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.