7 mm lead is thicker than the more fragile 0

but to extend the life span you can remove the filters from the mask and keep them in a tightly sealed plastic bag when the gas mask isn't being used

The ink locks chemically into the paper fibers

The Sakura XS125 mechanical pencil uses a 0

sized for a pencil pouch or a tight planner slot rather than a desk drawer

tombow mono graph mechanical pencil 0 5mm white Money 7 mm lead is thickerThe Tombow MONO Graph in full white uses a "Shake" mechanism to advance the 0. 5 mm lead: tip the pencil up and down and an internal brass weight drops to feed lead forward without breaking your grip. A standard side clip click works too, and sliding the clip up locks the shake function off for safe travel. The eraser at the top twists out rather than sitting as a fixed nub, and the fixed 4. 0 mm steel tip sleeve stabilizes the lead under heavier