SDC pioneered the revolutionary delayed egress locking category to the industry in 1985 before patenting and launching ExitCheck® 1511S series in 1995 – the world’s first delayed egress lock to integrate a visual digital display, verbal countdown and alarm tone, alternating verbal message and door release indicator. Since then, SDC has developed the premier line of delayed egress solutions offering the most choices, flexibility and customization available in the market.