This product is not nothing. For that price, it probably even has about 1ATM of air in it. Nothing? Ridiculous! Air has like 30,000,000,000,000,000,000 molecules per cubic cm! ref
Heck, even out in the midst of the voids there is still quite a bit of stuff around. Interstellar space has about 1 atom per cubic cm. Intergalactic, perhaps a few times less. So this sphere probably has at least half a dozen atoms in it. And even if they closed it up without any, the plastic would out-gas some over time. I see no rating for how long this cheap little sphere is expected to hold its nothing at various temperatures, or any of the other specifications I would expect to see from something actually containing nothing. And all this is putting aside the various photons (the darn thing is transparent!) and neutrinos (way transparent to those) and maybe some dark mater (depending on what that turns out to be).
Having spent more than a few hours considering the age old question of why there is something rather than nothing, I find this little gag-gift a bit insulting. As such, I recommend not buying this product.