The Hultafors Dry Marker HDM is a deep-hole marker that rides in a holster with a built-in sharpener.
The pen is shaped to reach into deep holes and tight spots, and it pulls out of the holster easily, so you don't have to let go of what you're working on. The holster holds the pen in place as you move, keeps the sharpener close at hand, and has a hole in the bottom that lets dirt and moisture drain away from the pen. The pen and holster both have a roll stop, and the lead is easy to change. It measures 164 x 21 x 28 mm. Refills of 10 leads, all graphite or graphite and chalk, are sold separately.
Hultafors started in 1883, when a young engineer, Karl-Hilmer Johansson Kollén, set up a factory on Folkungagatan in Stockholm to make the folding rule he had invented. The factory moved to Gothenburg and then, in 1907, to the village of Hultafors, between Gothenburg and Borås, where Hultafors still makes folding rules.