Privacy sets are which normally need to lock on one side. The One Side Plate has a Thumb turn on it, to lock the door, the second Side Plate has an emergency release. Privacy sets are used for bedrooms, bathrooms, offices, etc.
These come complete with Two Side Plates, Mortise Lock Body, all mounting hardware.
Also, for Double Coverging Doors, ( Two Doors coming together ), you would use One ( 1 )- Privacy Lockset and One ( 1 ) Dummy Set.