The Alpine Industries 9 in. x 3 in. Employees Only sign is easy to mount, easy to read with white lettering on a black background for optimal visibility. This pack of 3 signs is constructed of ABS plastic for durability and includes self-adhesive strips that effortlessly stick against smooth and flat surfaces and will not fade in extreme temperatures. These safety signs are sure to help keep out unauthorized personnel from certain areas of your workplace and ensure a secure work environment.