Square Contemporary Single Cylinder Satin Nickel Deadbolt Featuring SmartKey - 158 Series Designer style and superior security with this Kwikset Signature Series named Halifax. Square. Includes: deadbolt, bolt, strike plate and keys. Backset Dimension: 2-3/8 & 2-3/4 in. Maximum Door Thickness: 1-3/4 in. Cylinder Type: Single Cylinder Security Grade: Grade 2