Can you explain what you are after Mcafee used to supply a usb version on a particular memory stick I think they stopped that.
Will point a tech here
Moved this from home products to what I think is the appropriate area in Business.
Googling that part number (McAfee USB-STO2-4GBPFA - note: only one letter 'f') shows that they have been discontinued since last year. The best thing is to try online to see if someone is selling one. McAfee didn't sell them directly anyway I believe, but resellers did although I could be wrong there.
I see some merchants here in Canada still have other model numbers in stock.
Not sure if they continue to be supported either, which would be important. But since I've moved the thread to this area maybe someone else from the business section will answer that.