For a list of all currently documented Ralink chipsets with specifications, see Ralink.
Connector: Male A
Form factor tags: dongle
WI1 chip1: Ralink RT2571W
Product page (jp), Downloads (jp)
This looks to be a Gemtek manufactured dongle.
On Linux de kai @ wiki (JP)
Wi-Fi Certified (alt.) (as of 08/27/2007)