4.29" overall. Rectangular shape for writing comfort. 6mm low-profile body. Embedded micro socket provides a no hassle refill replacement that does not require tools. Accepts a wide variety of commonly available D1 stylus refills, including Fisher pressurized refills. No possibility of accidental ink retraction during use. Anti-roll design. Assembled from 24 individual, custom machined components. Integrated pocket clip. Black aluminum body with stainless guide rails. Boxed.