As the industry leader, Kwikset has provided trusted security for over 70-years and has become synonymous with security, peace of mind, style and innovation. The largest-selling deadbolt in America, the 600 series provides tough, effective protection at an affordable price. This single-sided deadbolt can be used along with a keyed knob or lever for added security, bolt is locked and unlocked by turn piece on inside of door. The Polished Brass finish adds to the traditional look and feel of the product and makes a classic statement.