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. If there\’s one pen that we recommend to new customers, it\’s the Bolt Action. All-metal, durable bolt action mechanism Three lengths: Standard, Short, Mini Available in Titanium, Copper, and Bronze Stainless Steel deep-carry clip Refill Included: Schmidt EasyFlow 9000 medium refill Specifications: Length:5.1\” Diameter:0.43\” Weight: Titanium:1.2oz | Copper:2.1oz | Bronze: 1.9oz Materials: Tactile Turn picked their materials because they\’re popular, fun to machine, and can withstand a lifetime of use. Titanium – Tough, lightweight, extremely corrosion resistant, and the best-selling material we work with. If this is your first Tactile Turn product, we recommend starting with titanium. Copper – One of the few metallic elements with a natural color other than gray or silver. Naturally antimicrobial, copper will patina and darken with time and use. Bronze – Consisting mostly of copper, tin, and other metals like aluminum, manganese, nickel, or zinc. Bronze machines beautifully and looks great when highly polished or with some patina.