ShinHan Art Touch Twin Brush Markers, Set of 12, Cool Greys (1211203) A perfect grip is due to the ergonomic design Fine brush nib on one end and a medium-wide chisel nib on the other Revolutionary design of the nibs safeguards loss of firmness from use Ink is refillable and replacement nibs in four sizes are available Alcohol based ink is odorless - non-toxic - permanent