Controller is built-in and designed for fire proof and smoke proof.
It can be fixed at anywhere.
Construction Input power: 24VAC or 24VDC Controller: With two wires, one is connected to the electric power (power supply) another one is connected to the fire equipment (system). When the input power is off, the curtain will automatically go down. Length of the beam: It can be depended on your need and the capacity of the outer roller.