Since Schlage invented the key-in-knob lock in 1925, the A-Series has been considered the “standard of excellence” in the industry. World-wide acceptance is testimony to the quality, precision, and design of Schlage locks. A-Series mechanisms are precision made of high-strength steel, plated for superior corrosion resistance and maintenance-free performance. A wide variety of functions are offered in a choice of knob designs and finishes. This series is ideally suited for quality residential and commercial buildings.