The Master Lock No. DS0603KA4S features a single cylinder deadbolt, with interior thumb turn. The deadbolt is four way adjustable for 2-3/8in or 2-3/4in backset, square, or rounded corners. The deadbolt offers ANSI Grade 3 performance for exterior locking applications. The polished brass finish provides a sleek appearance. Operates with SC1 cylinder. The Ten Year Limited Warranty provides peace of mind from a brand you can trust.