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 double cylinder deadbolt is operated by a key on both sides.The complementary Antique Brass finish offers a warm feel with deep accents in the contours of the product.