RSL & RSH FPCAP Capacitors Nichicon RSL and RSH FPCAP Capacitors are low profile, large capacitance capacitors that feature low ESR at a high frequency range. The RSL and RSH series offer high ripple current capability and are Pb-free and RoHS compliant. Nichicon RSL and RSH FPCAP Capacitors are ideal for switching power supplies, DC/DC converters, back-up power supplies of CPU (VRM, etc.), and miniature high power supplies.