This is the 661 model that also doubles as a robot mop when you flip out the dust bin for the water tank, and Now, a particularly affordable, Brand-name multi-function option ... When it comes to a robot vacuum you can trust, there really aren’t very many options that regularly sell in the $100 range ... You will Find some Amazon, but it’s hard to recommend those over an ECOVACS option that can both vacuum and mop for $100.