Pay attention to the dimensions!
For those who, like me, were intrigued by the difference in size between the description and what you can see on the picture (the pens have a standard length...), you should know that it's the picture that's right: the real inside size is 18x7x23 cm, but as the bag is made of fabric and therefore deformable, it's not within a few centimetres (in width and length).
Otherwise nice bag, full of pockets inside (and a large mesh one on the back outside). Construction looks solid (I have other Case Logic bags and I'm quite happy with them).