Try a Lamy Pico if you don't mind a ballpoint. No cap, it's small when retracted, click the mechanism, and bam...5 inch pen!
Is that a M300?This little Pelikan, just under 5", is my "go to.";View attachment 1329126
I always have a couple of compact ballpoints with me when I leave the house, but they're backups, and seldom actually get used. I'll always have at least one fountain pen and mechanical pencil as well.
The top row here shows my most compact fountain pens. Left to right: a vintage Waltham, Ohto Rook, A.G. Spalding, Stipula Passaporto, Pilot Petit 1, Kaweco Liliput. None of those are favorites, and only the Pilot and the Kaweco are at all likely to be used again. But they're all usable.
Continuing on, the two most compact fountain pens that are actually in my regular rotation, Pilot MYU and Pilot Elite. Both of those are actually inked right now.
Below that, the two ballpoints I mentioned. The Ohto Minimo is a gimmick, but works pretty well if you can hang on to it. The card that it's attached to makes it easier to find it in your wallet. Takes D1 refills, and is only a little longer than the refills themselves. And the old always there standby, a Fisher Bullet Space Pen. I actually have a couple of different Fishers, but always carry one with me, and keep another in the car.
And, not counting tiny stubs of wood pencils, the little no name mechanical pencil on the bottom right is the smallest writing instrument I have. I normally keep it on a key chain, and almost never use it; I have more practical pencils. Loaded with a 1.1 mm red lead.
View attachment 1329048
I think it is an M100, steel F nib. I also have a gold EF nib M200, pretty much the same pen otherwise.Is that a M300?
The level of trim looks like a late M400 (post-97 with a nib swap if steel) unless it's only about 4 1/3 inches for the M300 capped like @Jut pointed out except I don't recall a steel nib that fits those little guys. Def not the M100 or 150.I think it is an M100, steel F nib. I also have a gold EF nib M200, pretty much the same pen otherwise.
It was bought about twenty years ago if that helps, from Levenger.The level of trim looks like a late M400 (post-97 with a nib swap if steel) unless it's only about 4 1/3 inches for the M300 capped like @Jut pointed out except I don't recall a steel nib that fits those little guys. Def not the M100 or 150.
Nice pen.