The Belimo G250S-N+NFB24-SRX1 2" 2W 40 Cv S/R 24V Modulating is a high performance, 2" 2W 40 Cv S/R 24V modulating LED driver with a built-in frequency modulation (Fm) function. It is designed for use in high-power LED applications, such as backlighting and sign illumination. The Belimo G250S-N+NFB24-SRX1 2" 2W 40 Cv S/R 24V Modulating is a high performance, 2" 2W 40 Cv S/R 24V modulating LED driver with a built-in frequency modulation (Fm) function. It is designed for use in high-power LED applications, such as backlighting and sign illumination.