AJAX ReX Manual page 3

The communication range between ReX and the device is limited by the radio
signal range of the device (indicated in the device specifications
the website and in the User Manual).
ReX receives hub signals and transmits them to the devices connected to ReX,
and transmits signals from the devices to the hub. The hub polls the extender
every 12~300 seconds (by default: 36 seconds) while the alarms are
communicated within 0.3 seconds.
The number of connected ReX
Depending on the hub model, the following number of range extenders can be
connected to the hub:
Hub
Hub Plus
Hub 2 (2G)
Hub 2 (4G)*
Hub 2 Plus*
Hub Hybrid
Connecting multiple ReX to the hub is supported by devices with OS Malevich
2.8 and later. At the same time, ReX can only be connected directly to the hub
and connecting one range extender to another is not supported.
on
1 ReX
up to 5 ReX
up to 5 ReX
up to 5 ReX
up to 5 ReX
up to 5 ReX