A bit smaller but you can buy a 40″ from AliExpress. Though personally I think it is a way too pricy for a brand I have never heard of before. 
That link includes a video of it being ridden, which I will copy here (trimmed slightly as the file size was a bit too big)
EDIT: Hmm… despite not being present in the video it seems from the aliexpress link this comes with a disc brake. First time I have seen that on such a big narrow wheeled uni