Well it's a 0.1uF capacitor, but I'm not sure exactly what type it is. It looks a bit Russian to me. It's not going to matter massively what type it is for you, as you keep the tone control fully up. But if you ever used it, the large capacitance value means that it's going to go muddy very quickly. As I know you like bright tones, I'd keep it safe somewhere, but replace it with a smaller value capacitor, maybe 0.033uF or 0.022uF. The smaller the value, the brighter the tone.