The original penknife
A gentleman's pocket knife is the original penknife: they were used to sharpen the nibs of quill pens. Small, sharp, useful and, when concealed, will not disturb the line of your suit.
These small pocket knives are not just beautiful, but exceedingly practical. This Joseph Rodgers knife comes with polished buffalo horn inlays for the handle, and both a pen and pocket spearpoint blades. The knife is hand assembled in Sheffield, with its brass linings and pins complementing the nickel silver bolsters at each end of the handle. When closed, this gentleman's pocket knife is only 78mm long and weighs a mere 32g, so it can be slipped into any pocket with ease. A gentleman should never leave home without one.
My father has always carried one of these small knives and swears by it. He's very attached to it too. Recently he misplaced it at the bottom of the garden after opening some thick, heavyweight plastic sand bags with its small sharp blade. He complains continuously about losing it, and restlessly spends at least 30 minutes a day trying to find it; mum even takes him a cup of tea while he searches.
The only problem with these wonderful little knives is that they are easily lost.