Emergency Release Function: The crystal door knobs can be locked using the thumb button function from inside and be unlocked from the outside with privacy key in emergency Application: Typically found on bedroom or bathroom doors where privacy is needed, latch with locking mechanism, keyless Easy Installation: This privacy door knob is easy to install. All hardware, install instructions, and template included. Adjustable Latch: Latch can be adjusted to 2-3/8 or 2-3/4 inch, fits all doors 1-3/8" to 1-3/4" thick