XLR in XLR out 

Frequency band can be set by 'resistor set' - Buyer will be given the resistor details

I believe this was used on ATC 300 series but can be used for many active 3 way in the range

This unit has had a very recent (2024) minor date related service - All electrolytic caps replaced with Rubycon brand RX30 from UK Farnell (not fakes) . The three PSU axial caps also replaced like for like axial (not cheap radials) . One of output area 'Sprauge' caps (very high quality) was slightly off spec and so ALL were replaced like for like those are expensive so in the region of £150 parts cost . 

This work was done to help extend its life cycle.

ALL pots and switches appear to be original and a clean / service would be of use - expect movement and switch noise it is a working unit. 

This is a working unit BUT selling as 'spares/repair' only due to its age and to avoid the buy it, try it fraudulent return it! Technical images showing all outputs will be sent to buyer prior to shipping so you know its working (Sadly I have to list this way as a recent buyer abused the return process for a crossover).