Kamoer ATO ONE 2 is a compact, smart automatic top‑off device built for precise water level control in both marine and freshwater aquariums. Using an optical level sensor for normal refill and an overflow sensor for safety, it keeps salinity stable and prevents spills, all with minimal user setup. Alerts and status indicators notify you of overflow, timeout or low reservoir conditions, giving peace of mind when you’re away. The unit is easy to mount with magnetic brackets and runs quietly, making it ideal for nano to medium tanks where space is limited but reliability is critical. For hobbyists who want consistent daily maintenance without manual topping up, this ATO delivers practical automation, solid safety features and straightforward installation.