Dual power automatic switch is a newly developed miniature house hold power switch,which is mainly used to test whether the main power supply is abnormal, the standby power supply starts to work immediately. which ensures the continuity. reliability and safety of power supply. this product is specially designed for house hold rail installation and is specially used for PZ30 distribution box.Dual power automatic switch is a newly developed miniature house hold power switch,which is mainly used to test whether the main power supply is abnormal, the standby power supply starts to work immediately. which ensures the continuity. reliability and safety of power supply. this product is specially designed for house hold rail installation and is specially used for PZ30 distribution box.Dual power automatic switch is a newly developed miniature house hold power switch,which is mainly used to test whether the main power supply is abnormal, the standby power supply starts to work immediately. which ensures the continuity. reliability and safety of power supply. this product is specially designed for house hold rail installation and is specially used for PZ30 distribution box.Dual power automatic switch is a newly developed miniature house hold power switch,which is mainly used to test whether the main power supply is abnormal, the standby power supply starts to work immediately. which ensures the continuity. reliability and safety of power supply. this product is specially designed for house hold rail installation and is specially used for PZ30 distribution boxDual power automatic switch is a newly developed miniature house hold power switch,which is mainly used to test whether the main power supply is abnormal, the standby power supply starts to work immediately. which ensures the continuity. reliability and safety of power supply. this product is specially designed for house hold rail installation and is specially used for PZ30 distribution box.Dual power automatic switch is a newly developed miniature house hold power switch,which is mainly used to test whether the main power supply is abnormal, the standby power supply starts to work immediately. which ensures the continuity. reliability and safety of power supply. this product is specially designed for house hold rail installation and is specially used for PZ30 distribution box