We launched broadband source into 09 channel input, At the 09 channel output, we get same spectrum shape as manufacture test sheet of last two pdf links below, no power at the other output channels. From opposite direction, we also launched broadband source into 09 channel output, at the 09 channel input, we get same result as above, so there is no built-in isolator. We examined each side of the demux module, there are no electrical pins. So it does not requires temperature controller. See ITU grid definition in the 1st pdf link below. Made for Lucent WAVESTAR transmission systems. With LC/PC ocnnectors at each fiber end.