1. If your device's DC IN voltage is not in the options, please select the closest one. For example, if you device needs 5.5V, you can choose 5V or 6V. 7.9v you can select 7.5v.
2. It is a Center Positive + power supply. Please kindly check what polarity of your device before bidding. You can find the polarity information printed beside the power port.
3. If your device needs a Center Negative - power adapter, please kindly don't forget to buy one Belker Polarity Reversed Cable together. The wrong polarity may cause some damage to your device.
4. For AC to DC Power Adapter, normally, bigger one can be compatible with smaller one. For example, 5v 1a works with 5v 0.5a, 12v 1a works with 12v 0.8a. Conversely, NO. So please use it under 12W.
How to use correctly:
1. Check the AC adapter's DC output parameters and your device's DC in parameters. Please make sure they can be matched well.
2. Connect the correct adapter tip and make sure that it's firmly attached to the dc input port of your device.
3. Set the right DC output voltage which is corresponding to dc12v dc9v dc7.5v dc6v dc5v dc4.5v dc3v switch position.
4. Connect the adapter to the electrical receptacle and powering your devices.