Pica - Black Ink Marker For Deep Holes, Blister-Pack:  Qty 10 Marker for Deep Holes Ideal for spots hard to reach Marks on almost all kinds of dry surfaces Convenient quiver cap with special clip for perfect one handed handling Permanent alcohol-based ink , removable from glossy surfaces with alcohol and other usable solvents Works up to 24 hours uncapped Extended tip made of stainless steel ��� self-adjusting and patented: up to 3 times more marking capacity by using full 7 mm of the fiber nib���s length of abrasion, instead of 2 mm Nib can be twisted several times by 180�? - for up to 7 times & more Move the telescopic tip back with pincers The Marker with '7 lives' Tear out the nib wick and turn through 180�? Insert the nib wick again and move the telescopic tip forward Ideal Application Suitable Application Acceptable Application Note: Although some materials are suitable & acceptable we highly recommend using the markers for their Ideal application