The Diamond Mini Fountain Pen features a modern, eye-catching design, with a transparent body that shows off the pen's inner workings. About one inch shorter than the Diamond 580, the Mini is conveniently pocket sized, with a cap that can be screwed onto the back end of the barrel when the pen is being used. Its faceted barrel catches light and makes your ink shine, and it also helps keep the pen from rolling away. The piston filling mechanism is easily operated by twisting the knob at the end of the barrel counter-clockwise to extend the piston, submerging the nib in ink, then screwing the knob tight to retract the piston, drawing ink into the pen straight from the bottle. There's no need for cartridges or a converter.
The idea behind the TWSBI Diamond Mini was to go back to basics and capture the simplicity and elegance of traditional writing instruments. The Diamond Mini is a classically styled fountain pen with a piston ink-filling system, smooth-writing steel nib and a screw-on cap. The traditional mechanism of the fountain pen, combined with a modern industrial design, embodies both the past and the present.
TWSBI fountain pens can be entirely disassembled for the purposes of cleaning and servicing. Instructions and necessary tools are supplied with each TWSBI fountain pen but recommend this is only carried out by experienced fountain pen users. This should only be carried out as part of long term servicing of the pen; it will not need to be done straight away.