This Product Is Based On The Actual Needs Of The Family Factories And Pumping And The Detection Of The Pool (water Tower) To Control The Water Level To Achieve Control With A Small, Simple Wiring, Low Power Consumption, High Switching Capacity, Interference Is Strong, Functional Stability Characteristics Automatically Open When You Can Stably Pool (water Tower) Water Pump (solenoid) Pumping, Automatically Stops The Pump (solenoid) When Full Of Water This Product Can Be Used In Pond Water Tank, Garage, Basement Flooding Rains Place Where Automatic Drainage, Etc The Product Does Not Need To Buy Another Probe, Using Household Wiring Can Probe Size: 6x5x2.2cm Material:pcb Colour:blue Package Contents: 1 X Circuit Board Only The Above Package Content, Other Products Are Not Included. Note: Light Shooting 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.