- Built in noise reduction device helps reduce operating noise (not completely silent). - Compatibility and operation - Designed for aquarium walls with thickness -8 mm, with two states corresponding to wall thickness 5 mm or 6 mm. - Uses a differential pressure cut off mechanism. The water contact end has an oblique mouth, and there are a long and a short tube; the short tube defines the highest water line. - When the short tube is fully at the liquid surface, it begins to draw water and then stops filling. - Refilling bottle and threading - Includes its own water refill bottle. The threaded connection is suitable for domestic cola bottles and fits international standard cola bottles. - Application and compatibility - Suitable for refilling water in aquariums with cylinder wall thickness of 5/6 mm and -8 mm. - Fits international standard cola bottle. - Use scenarios - Evaporating freshwater aquariums (nano to small to mid size) where automatic top off helps maintain stable water level with minimal manual intervention. - Enclosed setups such as planted tanks or small tanks that require precise, low maintenance water replenishment.