https://forum.e-surfer.com/t/ultrafoil-what-a-piece-of-junk/
I purchased an Ultrafoil version 1 in January, 2019 from a vendor on eBay. What a piece of junk. Very cheap plastic latches on the battery compartment that are constantly breaking. The supposedly watertight electronics compartment leaks and when the electronics get wet they fail.
The electronics are cheap and failed rather quickly. I got a few good rides out of it when it actually worked but it is now broken and I have not been able to ride for months. The vendor promised to replace it but has not done so thus far. Don’t waste your money on this thing