The ES-911/USB is ESE master clocks that obtain date and time information from "Universal Serial Bus" port. The units are specifically designed to provide all of the time codes as described in the NENA (National Emergency Number Association) Standard NENA-04-002. These units easily interface to and allow synchronization of equipment such as CAD, ANI/ALI controllers, voice recorders and radio consoles. Both products can also synchronize other computers and digital/analog clock systems.