1. The electrode type water level controller adopts high quality electrode rod, which is encapsulated with plastic to form an insulating sleeve, and adopts anti short circuit design. 2. Using the conductivity of the water in the boiler, when the water level in the boiler changes, due to the contact and separation between the electrode rod of different lengths and the water of different water levels, the electrical circuit is closed or disconnected, so as to send out the signal reflecting the change of water level. Then the signal can be further processed. 3. The electrode type water level sensor takes the conductivity of water as the working principle, the sensing quality is stable, and it is not easy to produce wrong signals. 4. It can reliably receive and transmit the signal of the position in the water, has simple structure and long service life. 5. It can be used for a long time; it is not easy to corrosion and fall off; it can effectively resist the scaling problem; the maintenance is very simple and easy. Features: high temperature resistance 105 Celsius colour:White+red+blue Material:Probe: 304 stainless steel size:Red 1.5 meters, white 2.5 meters, blue 3.5 meters Package Contents: 1 x red sensor 1 x white sensor 1 x blue sensor Only the above package content, other products are not included. Note: Light 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.