Pack of 18 GIOTTO Turbo Maxi Super Washable Felt Tip Fibre Pens with a Large Nib of 5mm: The extra thick tip of these felt tip pens measures 5 mm in diameter. The pens' tips are particularly sturdy and resistant to pressure. Because of this, it will be a constant companion for your kids while they are in school. The 18-pen set includes all the colors required to make drawing more vibrant.