ScottKuma

You might also look at the amps that the device uses vs. the amps that the actual transformer provides.

If the transformer doesn't provide enough amperage (usually listed as mA - miliamps), the device may not work. For example, a wireless access point may need a lot of amperage while transmitting. Not providing enough amperage may make it LOOK like it's working, but may have serious effects during transmission. This will manifest itself as reduced range, spontaneous reboots during heavy traffic, etc.

Other devices may have problems if too MUCH current is provided. This can be a fire hazard. I had a problem with this once with old walkie talkies that I used another device's adapter for. The WTs got WAY too hot & eventually released the sacred blue smoke. (All electronic devices run on sacred blue smoke. If you release the smoke, the device will no longer work.)

Usually, the # of mAs on the device indicates the maximum draw the device will use. The # of mAs on the transformer indicates the maximum amount of power draw the transformer will provide.