This model uses the same nib as the Diamond mini and Classic ranges but nib assemblies for these models are not compatible with the Eco.
Nib length = 18.2mm
Section length = 23.5mm
Section diameter (max/min) = 11.3/9.2mm
Barrel diameter (max) = 12.9mm
Total length (not posted, including nib) = 132mm
Total length posted (including nib) = 167mm
Weight = 21g