The innovative Tombow Kei Coat Highlighter Ink Charger was awarded the grand prize of "STATIONERY OF THE YEAR" at ISOT 2003! The Kei Coat Highlighter is unique in that it does not take cartridge refills, but refills via "charging". To refill, simply place the chisel end of the highlighter into this bottle of ink and let it stand for a few minutes. Leaving it in for 1 minute refills the highlighter about 20%, 5 minutes for 70%, and 10 minutes for 100%. One bottle of charger contains enough ink for approximately 10 full refills, and one highlighter may be refilled up to approximately 5 times.