New type of electromagnetic device,electromagnetic part combines with armature plate.Integration of structure and function.Fail Safe.Build-in bolt&LED&release button.Bi-directional voltage feature.Technical feature description,all-in structure,its characteristic:die casting,all-in structure;Technical feature description,build-in bolt,its characteristic:applying principle of spring,bolt works as linkagewith armature plate;Technical feature description,bi-directional voltage feature,characteristic:12VDC/24VDC optional