Unlock with key from the outside when outer knob is locked by turn button on the inside, the inside is always unlocked. Dual option latch fits either 2-3/8" or 2-3/4" backset, 1-3/8" to 1-3/4" door range. Comes with 2 keys. Keyed alike when a full case is purchased. In accordance with California Prop 65 WARNING: Cancer and Reproductive Harm-www.P65warnings.ca.gov ADVERTENCIA: Cancer y Dano Reproductivo-www.P65warnings.ca.gov AVERTISSEMENT: Cancer et Troubles d l'appareil reproducteur-www.P65warnings.ca.gov - Lead