Essentially a robot with a tethered battery that can also solar charge. Says it takes like 2 days in full sun to charge if you just use solar. I was looking at the Aiper cordless robot as I love my polaris robot but the cord is kind of a pain. The Wybot is currently cheaper than the Aiper and I potentially don't have to even bother charging it if I just run it once a week. I don't know that I love the battery tethered to the top, but at the same point, you can probably grab that tether to get it out instead of having to go find the pole with the hook to get the aiper out of the pool.