Features of the Dissolved Oxygen Module include: Monitor/Control Dissolved and temperature. 6 digital inputs for float switches, water on floor sensors, pressure sensors, etc. Full datalogging support in Apex Base module. Up to 240 AquaBus modules can be added to the Apex system. Plug and Play. Automatically recognized when installed into the system. Two AquaBus connectors for flexible expansion via AquaBus Comes with 3? AquaBus cable. Galvanic Isolation for accurate and reliable probe readings. Led Status Indicator Upgradeable firmware. Compatible with all Apex systems.