The TWSBI 580AL is a staple product from the TWSBI company, a 580 dressed up with aluminum parts on the grip and internals, making for a classy and hefty fountain pen ready for daily carry.
The TWSBI 580AL has the same piston-filling mechanism as a normal TWSBI 580, but has an aluminum grip and internals (present on all AL models). The 580 stainless steel nib is interchangeable and has a screw cap (that does not post on top).