Kwikset Security 660 Deadbolt Series Satin Chrome Single Cylinder DeadboltAs 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 cylinder deadbolt is operated by a key on the outside or a thumb turn on the inside. The Satin Chrome finish gives the product a modern and minimalist look. For use on