The Full Sized Fountain Pen from Schon DSGN! I say full sized since it fits not just cartridges that fit in this pen but a converter as well. I personally love small pens so this was a design exercise out of my comfort zone. This pen uses a Schmidt K5 converter and houses a Jowo #6 nib. It was also designed to be a compact pen as that is my style. 

This pen is cross compatible with the Engineered Plastics Series meaning the parts are interchangeable across the pens. Ultem #6 grips, Rollerball/felt tip grips, Bock 380 Sections etc can be swapped between these pens. Find those here

Unlike the Engineered Plastics Pens, these pens are made out of Aluminum with an Anodized Finish and Should not be Eye-Droppered. Yes, it is possible to do it, especially if you swap in an Ultem Grip (with all those O-rings!) , but we do not recommend it since it can cause corrosion and many other nerdy reasons.  

The overall appearance and outer shape is the same as the Engineered Plastics Series, and dimensions are as follows. 

Capped length-127.5mm(5.02”)
Uncapped length - 122.5mm(4.80”)
Grip diameter min- 10.2mm (.40”)
Grip diameter max - 11.2mm (.44”)
Body diameter is 13.5mm (.530”)
Weight- ~0.9 Oz or 27 Grams compared to the Engineered Plastics @ ~1/2 oz or 14 grams 

The cap does "post" and the O-ring in the cap aids in that process. Keep in mind there is some metal on metal contact when posting the cap and that can cause some wear with extended use, so post with care or if that kind of thing will really bother you, hold back on posting frequently.