The CM-4/CM-4L is a high quality electronic low profile door chime that can be used as a stand-alone chime when activated with a push button. They can also be integrated with our complete line of people counters such as EBP-407C and EWP-202C. The CM-4L is a chime with LED light and is specially designed for the hearing impaired, and can be used in noisy and restricted areas where only the light signal is effective.