1. Small volume, sensitive response, no need for calibration 2. High precision and stable performance of liquid level control 3. Waterproof grade IP66 4. No mechanical moving parts, good optical sensing reliability 5. Wide range of use: suitable for mop scrubbers, coffee machines, water purifiers, water dispensers, pipeline water flow detection, etc Product Name: Pipeline Level Sensor Product function: Detect whether there is liquid in the pipeline Product model: PCFS-IR2125A-55 Pipe outer diameter: 5.5mm Inner diameter: 2.5-3.5mm Voltage: DC3.3V-5V power supply Supports water pipes with an inner diameter of 4-5mm Colour: Material:plastic+metal Package Contents: 1 * Water Level Sensor Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.