TWSBI GO Fountain Pen Smoke

The TWSBI GO in spring-loaded piston filling mechanism. This fountain pen is available in translucent blue and smokey gray body. With the clear grip section, the spring piston mechanism and the ink can be seen. The ink reservoir is inside part of the section as well as the barrel (rather than being the barrel itself), which needs to be unscrewed to fill the pen. The obvious innovation is the spring that is also inside the barrel, which holds the plunger at the top of the reservoir - unscrew the barrel, place the nib in the ink bottle, push down the plunger, and the spring does the rest. If you have a look at TWSBI's video, below, it's really quite spectacular.

Another difference from previous pens from this manufacturer is the cap - whereas TWSBI's pens have always been screw-fitted, the cap on the TWSBI GO fountain pen is push-on.

Note: This pen only uses bottled ink, which is not included with this pen.

A quick no brainer guide in choosing nib sizes in an overly complicated fountain pen world:

If you write small, go with an EF
For the normal writer, F is the most popular
If you tend to lean on a bigger font, M will be perfect
B is for statements!! Sign a check in B, write a header in B, do some coloring/shading in B
Stub nibs are italic in writing style (have a special card or invitation to write?)

Specification

Nib Size Chart