Scully tank fill signals are the original whistle-stops. They whistle when the tank is filling. When the whistle stops, the tank is full. The calibrated whistle stems allow for product expansion and may be cut for flat style tanks. A patented screen keeps the whistle chamber free from pipe scale and bugs. Scully fill alarms stop costly spills and prevent ruptured tanks while improving your delivery efficiency. They are completely reliable and accurate. A one time installation usually outlasts the life of the tank. Models are available for most every type of tank installation.