Need for right Power Supply

Today, we are using many electronic devices which work on the different power supplies. To solve this problem we need help of right adaptors because we get the main supply at a constant voltage. Recently, I needed a 9v power supply for one of my device; however, I failed to find an adaptor with such specifications in the local market. So I bought one from the online store. These small essential adaptors are very useful to run a number of electronic devices. Small electronic devices like eye massager, broadband modem etc run on 9v power supply.