Billed by OHTO themselves as the world's most complex mechanical pencil - and these are the guys that gave us the Super-Promecha - the Conception is capable of transforming from a capable drafting pencil into a sliding-sleeve writing pencil. All whilst maintaining lead-advancement adjustment capabilities. The lead advancement is a rotary control at the end of the barrel which, when rotated, allows the pencil to advance more, or less, lead with each press of the push-button. The amount of lead advanced with each click can be controlled between 0.2mm and 2mm, according to preference. An indicator on the barrel of the pencil shows the current setting. The unique feature that lets the Conception change from a drafting into a writing pencil is controlled via the grip section. The grip section can be moved forwards or backwards, either reducing or increasing the length of the lead tube to your preference. When the lead tube is wholly retracted into the barrel of the pencil, the sliding sleeve feature becomes available. Each press of the push button will now extend the lead sleeve to its fullest length, whilst writing with the pencil will now gradually wear down the lead, and push the sleeve back in as you do so. Certainly a pencil fit for the fearless!