... Level Switch 1.Low cost: cheap material 2.long life:>1000000 times 3.working temp:-20~+125 4.Certificates: CE, RoHS,FDA Level Switch ... float ball moves along the stem with the water level, the magnet inside the ball will cause the action of the reed switch ... the float switch, to prevent overflow or to prevent dry-fire. Application:water heater, water dispenser, air-condition, air-cooler, BSD-P, ...