These pens by London designer Sam Hecht of Industrial Facility are hand-carved from hard rubber.

Available as a rollerball or fountain pen, the Pentagon has a five-sided barrel with a smooth cap that covers most of the shaft.

The cap has a double screw-thread so it can be turned in either direction and the gold nib is by artist and nature artist Tham Pui San.

Hecht designed the set for Singaporean pen company Elephant & Coral and they're available from the designer's own website, Retail Facility.

Here are some more details from Industrial Facility:

Pentagon Pen Collection

In our increasingly digital world, writing instruments still seem to hold their position as anchors of reality. The Pentagon Collection consists of a fountain pen and rollerball pen that represent characterful simplicity, borne from patterns of use. The spherical cap transforms the pentagonal barrel into a seamless pen when the cap is screwed over it (a two-way thread allows the cap to turn in both directions). Pentagon is made from polished Ebonite - a very hard rubber - that is shaped and formed by hand. The pentagonal form itself is made of an odd number of facets that only a skilled craftsmen can produce. The nib is made from 18K gold, with a specially commissioned nib design by the artist and naturist Tham Pui San.

About Industrial Facility

Industrial Facility is a design office based in London and formed by designers Sam Hecht and Kim Colin. They have developed projects for among others, Herman Miller, Mattiazzi, Issey Miyake and Muji. What binds their work together is a belief that simplicity can be inspirational. They have won numerous awards including ‘Design of the Year, 2011’ for furniture, awarded by the Design Museum; Designers of the Year 2010, by Elle Decoration; and the IF Hannover Gold Award on three occasions. Their book ‘Uselfulness in Small Things’ was published by Rizzoli in 2011. Sam Hecht was made a ‘Royal Designer for Industry’ in 2009.

About Elephant & Coral

Elephant & Coral was established in 1996 as a small, fine pen company in Singapore, and is a leader in the retail of fine writing instruments. The name "Elephant & Coral" is derived from a place in London, Elephant & Castle, where the founder spent some of his best years of education in England. In their endeavour to bring forth different writing experiences, they commissioned a pen collection from Industrial Facility. Elephant & Coral believes that writers in any era need to be encouraged and motivated to extend their dreams. Since their inception they have provided pens to established and emerging writers in support of their published literary works (fiction or poetry). With a symbolic gesture they honour and encourage many of the unsung heroes who continue to inspire us through their writings.

Producer: Elephant & Coral, Singapore, 2011
Design: Industrial Facility
Material: Polished black Ebonite with 18k gold nib
RRP: £695