OTR .071 Cold Sweat Marker. It comes filled with Hard to Buff ink and Bitumen. This mixture of ink is clean and runs really smooth. The nib is a .8″ “T tip” which can be replaced when it wears out. The marker is also refillable. Pump-action are always nice and insures your ink is flowing when needed. Bitumen is the chemical used with tar when creating asphalt. Needless to say, streets don’t fade.