Keep your markers ready to go at any moment with the Set A Artist Marker Refill by Altenew! The package includes 12 alcohol-based marker refills. Each bottle measures 30 ml and can refill a marker up to 10 times. You'll love how easy it is to use, too! Just remove the brush nib with a pair of tweezers, position the tip of the refill bottle right above the open barrel of the marker and fill the marker with 8-10 drops. Reinsert the old nib or replace with a new nib and you're done!