Rite in the Rain M973-KIT Weatherproof Side Spiral Kit:

This all-in-one TPU cover offers durability and versatility with elastic spinal holders for extra books, secure webbing closure, and interior storage pockets for cards, papers, and phones. Equipped with three pen holders, a webbed spine loop, a weatherproof side-spiral notebook, and a tough 1.3mm mechanical pencil, it’s perfect for keeping your essentials organized and protected, no matter the conditions.