Pierre Cardin Pen & Pencil Sets with Gift Boxes (Pack of 3) Mechanical Pencil Operations - To write, press top advance lead. For 07.mm lead, unscrew upper barrel from lower barrel to separate, remove the plastic cap and slide new lead into the plastic reservoir. For 0.5mm lead, to erase pull top to expose eraser. To replace lead, remove eraser and slide new lead into the plastic reservoir. Ballpoint Pen Refills - Simply pull cap from pen barrel. Remove empty refill by turning counterclockwise. Replace by inserting refill and turning clockwise to tighten. Refills are compatible with Cross cartridges