The Art Primo Big Squeeze Mop writes big and with a squeeze can give you some juicy drips. This 4oz heavy-duty squeeze marker features a 1" round sponge nib that will write on most surfaces. Replacement nibs are also available and can be easily replaced. The Big Squeeze also features a threaded cap that is more reliable and means ink won't leak out of the marker. This 4oz marker is sold EMPTY. So just fill it with your favorite ink like Molotow Cocktail, Molotow On 4 All ink, or Smash Ink. This marker is REFILLABLE.