The output amplifier stages are based on high performance 1.2 GHz GaN hybrids, which ensures highest possible signal quality and high output level. Interstage gain can be controlled in two positions, which results in wide operational dynamic range. The first stage is adjusted by OLC function. The second slot(s) can be controlled with plug-in attenuator and equaliser modules. The integrated microcontroller takes care of OLC and monitors RF levels, laser bias current, temperature and supply voltages and transmits alarm data to the head end. Status leds for optical power and RF levels provide status information for true plug-and-play installation. Fibre organizing is made in the lid, which includes splice organizer with 12 holders, connector holders and fibre in/out ports.