I'm pretty sure that's a JP power supply, but I wouldn't use it. Buy the Radio Shack 273-1771. Its totally perfect for the Duo R/RX at 9v 1500ma. Its kind of expensive but getting a 9v ps with a rating of 1A or more is really not as easy as it used to be since most modern devices don't suck that much power.
This PS is even white, so it maches the Duo, which not even the original NEC one did.