This is a negative non-review.
(Is that a double negative?) 
No, I did not by it or try it,
so I can not write a review.It seems Xtra-PC (tm) is doing more advertising for a product about three years old . But it was never really original product.
Yes, you may already know about it. This is for the befit of new comers who might be caught in the smooth advertising done by these people.
Short story: Don't buy it. You don't wan tit. The advertising is very closet o the line between promotion and deception. Decide for yourself which side of the line.
You can search for
Xtra PC and find both the web site and ads from Amazon and others to sell you the USB thing for about $35 to $50. What you get is a nice looking USB stick with a modified Linux system. And a promise to give you support to help you repair your PC.
Here is an old reviews from CNET, which is very negative.
https://www.cnet.com/forums/discussions/has-anyone-heard-of-xtra-pc/One poster had this positive remark::
I like their sales pitch.
Yeah, the posts are old, but there is no reason to think the product has become better.
Now if you want Linux on a USB, that has been well covered elsewhere and it will cost you nothing . You use any USB storage device you want.
My personal choice is an very old Laptop PATA drive from a broken laptop. Works great with Ubuntu 16. Similar versions of Linux also install on any USB storage device. The trick is to learn how you get your BIOS t o boot from USB.There is not reason to pay $35 to $50 to have somebody tell you how to boot from a USB stick.
