This is a Mini stainless steel float swith,contains no mercury. This float switch is a device used to sense the level of liquid within a tank,the switch may activate a pump,an indicator,an alarm,or other device. This Mini float switch is a simple structure,easy installation liquid level controller. It does not have a complex circuit, not be ,as long as the material selection,liquid,pressure or temperture can be used in any environment. Light weight and simple working principle,high reliability. The versatility of this vertically mounted sensor means that it can be installed either at the top or base of your tank,depending on whether you wish to detect the water rise or fall. The float level switch is widely used in electronic,electrical,chemical,water treatment,drainage and other walks of life level control and alarm. Product Name: Float Switch Material: Stainless Steel Net Weight: 492g Max. Breakdown Voltage: DC 220V Max. Switch Current: 0.5A Max. Switch Voltage: DC 100V Max Wattage: 10W Temperature Range: Low temperature 0-60 Celsius Max. Contact Resistance: 100m Ohm Thread Size: 10mm/0.4 inch; Float Ball Size: 28 x 28mm/1.1 inch x 1.1 inch(L x D) Wire Length: 30-40cm Total Length: 528mm/21 inch package content: 4 x 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.