RLS/M burners are characterised by a modular monobloc structure that means all necessary components can be combined in a single unit thus making installation easier, faster and, above all, more flexible. The series covers a firing range from 1120 to 11500 kW, and it has been designed for use in hot water boilers, overheated water boilers as well as steam boilers. Operation can be “two stage progressive” or alternatively “modulating”, for both fuels, light oil and gas, with the installation of a PID logic regulator. The mechanical cam device of regulation allows to catch up a high modulation ratio on all firing rates range. The burners can, therefore, supply with precision the demanded power, guaranteeing a high efficiency system level and the stability setting, obtaining fuel consumption and operating costs reduction. The combustion head guarantees reduced polluting emissions (NOx < 80 mg/kWh on gas operation). An exclusive design guarantees low sound emissions, low electrical consumption, easy use and maintenance.