This unique 50 caliber project not only adorns your desktop with an authentic once fired 50 caliber bullet, but flip the inside pen out for a unique and convenient writing instrument. An actual 50 caliber shell (included) acts as a holder/sleeve/stand for the easily removable pen inside. Features a solid copper bullet tip. The kit uses o-rings to seal in the refill for a guaranteed long refill life. Includes a smooth writing Roller-ball refill.