The unique bolt action shape allows for one fluid motion to advance or retract the refill. Because the surfaces of both the interior part and the inside surface have been carefully machined to be extra smooth, the action feels amazingly satisfying, now in a slimmer, lighter body. Copper is naturally antimicrobial and develops a rich patina that darkens with time and use. The Slim adds a milled, deeper-carry clip and the same 'Tactile' texture, so it ages with you wherever you carry it.