The Dulo-Dulo, or palm or pocket stick, is easy to use and suitable for personal protection. They're not a new tool at all, as they've been used for self-protection tool in the Philippines for generations.
Each one is hand-crafted in the Philippines and polished to a fine finish. They're approximately 17 cm. long, made from natural material, and are lightweight and unobtrusively carried in a pocket, purse, or other bag. You'll want to consult your local law enforcement to see if you can carry this, of course.
If you're able to carry this you'll want to keep this item close at hand, because if you can't reach it, you can't use it. If your laws prohibit carrying this you'll have a long-lasting training tool that can equip you to export your training into similarly sized items outside of training lab conditions.