In Writing, To Protect The Core So That It Does Not Break Even From No Matter How Strong The Pen Pressure Of Every Angle. For The Paper, The Vertical Strong Writing Pressure Is Applied, Spring Which Is Built In The Axis Prevents Broken Missed Upward The Core. When The Strong Pen Pressure Is Applied At An Angle, Metal Parts Of The Tip I Will Guard Wraps The Core Come Out Automatically. The Two Mechanisms, Works By Adjusting The Allocation Automatically To Match The Power Of The Angle And Strength Applied. (※ From The State In Which The Core Is Not Out, It May Break It And Write To Knock More Than 4 Times.).