Rite in the Rain's All Weather Top Spiral Bound notebook is a shirt pocket format notebook with all the advantages of RITR Paper.
Rite in the Rain says:
The global standard for tactical colored notebooks. Protect yourself and your notes by using the Rite in the Rain Tactical Pocket Notebooks. These 4 in x 6 in spiral bound notebooks have 100 Universal pages (50 sheets) in Green or Black. With the Universal Pattern you can use this text for notes and scaled drawings. Useful reference material is also printed on the back and inside covers.