Feature: 1. STAINLESS STEEL MATERIAL: Our liquid level sensor is crafted with a premium 304 stainless steel casing and highly sensitive reed switches. 2. DUAL FLOAT SWITCH: The dual float switch has a 10mm action range, allowing for a wide control range. You can combine two float switches for longer strokes, reducing the pump's frequency of operation. 3. EFFICIENT WATER CONTROL: The lower float switch is activated during normal water inflow, while the upper float switch controls the draining process. This ensures smoothly and effective water management. 4. ADDITIONAL RELAY REQUIRED: To control electromagnetic valves or high performance relays, an additional small relay (like the for HH54P, not included) is required for seamless transition and optimal performance. 5. VERSATILE APPLICATIONS: The water level sensor is suitable for controlling liquid levels or activating alarms in water tanks, pools, reservoirs, and aquariums for both inflow and outflow scenarios. Specification: Item Type: Double Ball Water Level Controller Material: Stainless Steel Size: Approx. 150mm / 5.91in Voltage: 0-110V Cable Length: Approx. 400mm / 15.75in. Package List: 1 x Double Ball Floating Switch