Sunderland Machine Works mk1
Deep posting pen that has internal threading for Montblanc rollerball refills. The cap is lined with plastic to eliminate metal on metal contact when posting. Innovative cap thread location inside the groove between the grip and tip ensures they are out of the way. This is one of my top pens.
Variants: A range of anodized colors and electroplated nickel.
Refill: Made for threaded Montblanc rollerball refills. Also fits Pilot-style G2. I have a Pentel Energel hacked into one of them.
Clear Anodized
Nickel
Gentleman Stationer version