Abstract: A holder tube for a writing instrument in which a plurality of rings having external faces subjected to different treatments are removably disposed in at least a grip portion of the holder tube. In another form of holder tube for a writing instrument, a plurality of rings having non-circular external faces are disposed in at least a grip portion of the holder tube in such a manner that the state of each of the rings differs from that of the adjacent one. In another form of holder tube for a writing instrument, at least three rings having different diameters are removably disposed in at least a grip portion of the holder tube. In a further form of holder tube for writing instrument, a ring or rings having longitudinally different external shapes are removably disposed in at least a grip portion of the holder tube.

Abstract: Connectable writing instrument composed of two component writing instruments of the same configuration. Each of the component instruments comprises a body, a holder section adapted to hold a pen component at the front end of the body, a front reception hole arranged parallel to the holder section, and a rear reception hole arranged in line with the pen component or with the front reception hole and an engagement projection at the rear of the body. The holder section and the engagement projection engage with the front reception hole and the rear reception hole, respectively, or vice versa.