Door Push Bar Panic Exit Device Lock Hardware Latches! NoteThis product must be installed indoors. Only doors that are pushed outside can be installed.Anybody in the room can push out, and people outside come in with a key to open. No one can get in without a key.Note: Heavy Duty Commercial Rim Exit Device For 30"-36" single Door, DOES NOT SUIT glass doors.Installation steps:1. Measure the position of the lock core2. use 35mm drill to punch a hole3. open a suitable lock core hole4. fix the lock5. insert the product onto the lock rod and fix the lock securely6. Fix the head cover7. fix the tail iron cover8. Cover the tail cover9. Try if the the lock outside cylinder can open normally10. Lock the card to the appropriate location ,and then you have fixed a single door unlock successfully