As TTT posted, if the total length of the wiring for the system is over 600ft you need the filter call 1-800-222-3111 for info on the filter. The guide says that the 944 is fully compatible with the 964 or 955 units. You can use a total of 12 sets. If you would like the guide I can shoot it to you.

As Ken posted you must assign them a intercom number from 11 - 22, the batt is for holding the programming in case the power goes out so if your batt is bad and you unplug the power for some reason you will have to program the set again.


Russ runs a local service and private tech center.

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