-Vertical direction
Upward force on lead.The vertical pressure and force on lead triggers the lead to release upwards,adding protection.
-Oblique direction
Angled force on lead.Pushes the nose piece forward, adding protection.
-Hard to jam
Generally, short leads get caught between the gap and break.
However, the 'DelGuard System' protects the lead allowing you to keep writing without fear of the lead breaking