Hillman Black & White Door Must Remain Locked Sign a clear and highly visible warning for important entry and exit points. Made from durable vinyl with a self-adhesive backing, this sign is easy to apply and measures approximately 1-1/2 inches wide by 28 inches long, making it suitable for a variety of door sizes. Designed to ensure safety and compliance, it effectively communicates the need to keep doors locked during business hours. Proudly made in the USA, this sign combines quality and functionality to meet your security needs. Model Number: