"Iskra KSC is a classic polystyrene (Styroflex) film capacitor in a brown epoxy-dipped, non-inductive construction— prized for ultra-low dielectric absorption, very low loss, and excellent stability. Ideal for precision audio (RIAA, filters, coupling) and timing networks; not intended for high-temperature service (typ. up to ~70 °C) or mains-safety use. Often found in tight tolerances (±1–2%) across 50–500 V ranges."