Installed on hollow metal doors, plastic-steel doors and other sliding rail type doors and  windows. 
The standard appearance of the structure apply to various brand hollow metal and plastic-steel doors and windows.  
The fixed installation parts can be installed on the frame, cylindrical assemblies embeds in the  frame, easy to install.
There are anticorrosion coating protection for Latch bolt components and Lock bolt.
The Fail safe feature design, meet with the demand  of emergency exit.
The special usage design, during the product life cycle, it don't need to do preventive maintenance and lubricant, etc.