HSC ST840-18KW - 130 bar, 11 litres per minute, 400 volt. HSC ST ST840-24KW - 130 bar, 11 litres per minute. HSC ST1140-24KW - 230 bar, 16 litres per minute. HSC ST1140-30KW - 230 bar, 16 litres per minute. All models have a fully insulated stainless steel cabinet, total stop / start system, 24 volt safety circuit, leakage recognition, hour counter, flame failure sensor, hot water resistant triplex pump, electrically heated means emmission free.