A magnetic wall detector operates without any batteries since it uses a rare-earth magnet (or magnets). It doesn't actually detect studs but instead locates the nails or screws attached to the wood.
solenoid valve applied in automatic control system, such as pipe of public water work project, sensor shower, solar heater water self-motion, washing machine, sensor sanitary ware, shower, garden irrigation, prepayment water.
Quick fitting applied in automatic control system, such as pipe of public water work project, sensor shower, solar heater water self-motion, washing machine, sensor sanitary ware, shower, garden irrigation, prepayment water.