Pica Ink Deep Hole Markers have a long nose to easily get into deep holes and other hard to reach areas other markers can't. The permanent alcohol based ink dries instantly and is resistant to abrasion and water, and makes marks on nearly any dry material The long patented tip is made of stainless steel and self-adjusting, providing up to three times more marking capacity by using the full 7 millimetres of fibre tip instead of just the 2 millimetres visible. Use a pair of pliers to extend the life of the marker by: Moving the telescopic tip backwards Tear out the nib wick and rotate 180 degrees Insert nib wick Pull telescopic tip forwards Included with each Deep Hole Marker is a quiver cap with an extra-strong clip designed for secure attachment so the pencil can be easily withdrawn and replaced with just one hand.