Industrial telecommunications data transmission module

Industrial telecommunication data transmission module. It has a "REF - OUT" connector and a "Data TX" LED" It measures about 4 3/8" x 1 3/8" x 6 5/8".

This is from the estate of an industrial telecommunications engineer and ham radio enthusiast. We don't know much about it and we have not tested it.

this item no longer available
Item No. n24470