LL1584-3FX3MX is a transformer isolation unit. The LL1584-3FX3MX is used to break up ground loops in balanced systems, for instance to eliminate hum when connecting active speakers.

Transformer turns ratio 1:1
Connectors: XLR-F — XLR-M
Cable Length: No cable
Max Prim. Level. 1% dist, 50Hz: 17 dBU

Complete datasheet for LL1584-3FX3MX