The JS-1HD is a sub master station for the JS Series. The JS Series is a single door, 2 master station system. The master station and sub station features a 3.5" screen and buttons allowing for door release and monitoring of the door station.

The JS-1MD master station and JS-DA door station are only available in the JSS-1A kit. The JS-1HD sub master station can be added to the kit to expand the system to its maximum capacity of 1 door station and 2 inside answering stations.