Thank you for viewing. This is the latch body for an interior door by Kawaguchi Giken (GIKEN). Backset (distance from the door edge to the center of the handle): 55mm Square spindle hole (core of the doorknob/lever): 7mm I purchased this after measuring, intending to replace it at home, but it was not compatible because I measured incorrectly. I opened the package and inserted it once. The screws were used, so they are not included. - Model: DR-55Z - Backset: 55mm - Square spindle hole: 7mm - Manufacturer: GIKEN - Application: Interior use