Can someone tell me what this is?

[shivy]

http://www.rocom.co.uk/catalogue/index.cfm?event=catalogue.product&productID=20056&categoryID=1192

Is it just like I plug it into a notebook and it increases wireless strength?

 

[Law]

It's just a USB wireless adaptor. The 140Mbps that's what they meant to advertise but got it wrong is the maximum speed the card can support with the speed booster technology. The speed you will get depends not just on the card, but your wireless router and other factor like your environment and interferences.