Parameter --- For 12V to 5V voltage regulator: Input voltage: DC 4.5-20V; Output voltage can be adjustable or fixed. Adjustable range: 1-16V; Fixed voltage: 1.8V, 2.5V, 3.3V, 5V, 9V, 12V; Output current: Max 3A (: 3A, long-term: within 2A); Power: 10W.Output Voltage Adjustable or Fixable --- These tiny 12v to 5v converters can be variable at output voltage. The small board is default to be used for output voltage adjustment. If you want to get fixed voltage output, you need to cut off the Pad A by using a sharp thing such as a knife then weld together the port of the fixed voltage you want.High Efficiency --- Conversion efficiency: Up to 97% (typical value: Greater than 90% when 12V to 5V 2A).Protection and Enable Control --- Output short circuit protection, but please do not keep short circuit for a long time. The integrated enable port defaults the working mode and it will be off when it is at low electric level off, which bring a great convenience for users.NOTE --- This mini buck converter is very tiny, much smaller than a 1-dollar coin, nearly a half of the coin.NOTE:Please be gentle, the potentiometer is quite weak. You may use a sharp plastic piece to get it work if there's no suitable tool.Colour:blackMaterial:PC, MetalSize: 14 x 19.5mmPackage Contents:6 x DC Buck ConverterOnly 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.