I bought a drop pen from a Bernina dealer. I thought too expensive at the time but now I know it was worth it. It's refillable and has never leaked. ( The last time I looked at a new one it wasn't refillable! Bad Bernina) Be sure you can see the color of the oil in the container. Any color at all, don't use the oil. It has to be clear. Yellowish oil will be sticky and gum up the works.