For a list of all currently documented Realtek chipsets with specifications, see Realtek.
Connector: Male A
Form factor tags: dongle
WI1 chip1: Realtek RTL8187L
WI1 chip2: Realtek RTL8225
Product page, Drivers
Adapter apparently orignally came bundled with an ADSL router (which appears to be a Billion device).
It appears to be a Loopcomm device, but the OUI is of Billion.