Pilot Birdie Twin is a slim, beautifully styled, stainless steel pen. It is a 2-in-1 multi pen, combining ballpoint pen with a mechanical pencil combination. The ballpoint pen has a ball diameter of 0.7mm and the mechanical pencil uses 0.5mm pencil leads. The pen weighs up to 7.3g. It comes with a black ink for ballpoint and is ideal to use for pocket diaries, or as a gift for someone special.