mEh. Those are "Giatex" brand stretching bikes.

For starters, do all of us a favour, including yourself: if you DO buy a product, go out of your way to NOT buy it from whoever spammed you. In the long run, if everyone makes that choice, spam will dry up.

I rode a 16" and 20" wheel Giatex at an airshow about a year ago. Not bad - seemed like a good value for the money. Components were comparable to what you'd find on a Dahon or similar bike of the same price category (entry level but not "Wxxlmart")
Seemed like a good value. They were offering them discounted at the airshow for something like $350CAD.
"Target" stores in the US have them for $350US. See this link.

Visit their main, international website for the definitive source of info on their bikes and, presumably, a list of NON-SPAMMING DEALERS!

I suspect they'd hold up well as there's no hinge to wear out and the slide was pretty beefy, being the frame and all.

There are some online reviews of these bikes so you can opinions before you buy - and as with all bikes, TRY it before you commit. If you can't find one where you live, either take a trip somewhere that has it or look at other brands.

Review #1
Review #2

A review I did of several folders - more of a "mini-buyers guide" that included the Giatex and a number of others.

...and a good site for advice.