Each refill bottle will refill a Spectra AD Marker 8-10 times, extending the life of your marker! The bottle has an ergonomic shape with gradations that mark the volume of the refill in milliliters, so you know how much you are filling your marker. The easy pour spout is designed to fit into the marker once the nib is removed and only takes seconds to refresh your marker. The alcohol ink refills may also be used alone, the spout acts as a dropper to apply to paper, or to pour into a container and apply with a brush. Mix with other Spectra AD Alcohol ink refill colors or the Blender to lighten colors. How to refill a marker: 1) Match the marker and refill number 2) Expose the chisel nib of the marker and remove the nib with tweezers.