The second finish in TWSBI's Precision line, a metal-bodied piston filler drawn from the drafting tools of architecture and engineering studios. The body, cap, and grip are blue anodized aluminum, cut into a six-sided profile with polished bevels between the facets — so the pen reads as two-tone, a steely blue against bright silver edges that shift as the light moves. Chrome-plated clip, finial, and rings finish it. Named for the constellation, and a limited edition alongside the standing gunmetal version.
What makes it special
Two-tone effect built into the shape: blue anodized faces with polished silver bevels between them, rather than applied decoration
Machined aluminum body and grip — heavier and more solid than the resin ECO or the acrylic 580 at 30 g
Hexagonal barrel with an angled clip, a departure from TWSBI's rounded demonstrator shapes
Ink window in the grip section instead of a clear barrel, for a more discreet look on a desk
Piston filler holding about 1.0 ml, filled straight from the bottle with no cartridge or converter
Two o-rings on the piston knob so the cap posts securely rather than sitting loose
Fully user-serviceable; ships with a wrench and silicone grease for disassembly and maintenance
Specs
Type: Fountain pen, broad nib
Nib: German-made stainless steel
Body, cap & grip: Blue anodized aluminum with polished bevels
Filling: Piston (bottled ink only — no cartridges or converter)
