Aghh It's so frustrating! It's the last part of my tesla coil (besides the control box) and also the hardest to find and get. Someday though I WILL FIND SOME!That's usually because they find just the right capacitor to make up their resonant tank cap which is convenient. This is definitely the most difficult part for me when I'm building a Tesla coil - finding a resonant capacitor. It's still difficult for me to this day.