before you purchase a gun for self-defense, please pause to reflect. Your weapon is much more likely to end up being used to harm than for good, even if you’re one of the “good guys.” The odds are not in your favor.
Chronodex is a personal time management system developed by Patrick Ng that naturally matches the clock. It's free! Here's the printable 2015(a) edition sized for Traveler's Notebooks
For the list-makers, the note-takers, the Post-It note pilots, the track-keepers, and the dabbling doodlers. Bullet journal is for those who feel there are few platforms as powerful as the blank paper page. It’s an analog system for the digital age that will help you organize the present, record the past, and plan for the future.
Mike Rohde of Sketchnoting fame hacked a Pentel Energel refill (normally a Pilot G-2 sized refill) to fit into his Retro 51 by trimming the end of the refill to be the right size. If you’re willing to experiment, other refills might also survive this sort of hack. I’ve hacked the end off a few refills in my time to make them fit as well. Just grab a craft or utility knife or a sturdy pair of scissors, line up the old refill and the new refill and snip. Voila.