Wireless intelligent door detector (with lithium battery)DescriptionName: Smart Wireless Magnetic ContactModel: XSJ-87JKey Features:1.Smart door/window magnetic contact for smart zone application2.Wireless magnetic contact with panic button.3.Wireless magnetic contact with smart mount bracket design,Website:http://www.home-security-life.com, easy to installation and maintenance.4.Powered by rechargeable Li-ion battery, can expand the usage of life-span.5.On the back with power ON/OFF design and built-in recharge jack port.Technical Parameters:Operating voltage: DC 3.7V, Powered by Li-ion Rechargeable Battery.Standby current: