As the industry leader, Kwikset has provided trusted security for over 60 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 cylinder deadbolt can be locked or unlocked by a key on the outside, or the turn piece on the inside. The Polished Brass finish adds to the traditional look and feel of the product and makes a classic statement.Bacteria can double every 20 minutes on an unprotected surface. Microban silver glass technology is incorporated during the manufacturing process and permanently binds the silver ions to the coating. Treated hardware continuously inhibits the growth of bacteria on the surface creating a cleaner product. Homeowners that install Kwikset hardware with Microban antimicrobial product protection are proactively protecting a frequently touched door surface, which helps to reduce the growth of microbes on the surface of the hardware.