After my dog was attacked by two Pitbulls, I got a 31" stainless ASP baton. My baton is pretty heavy, and I've added a mushroom buttcap. I mounted in to my bike frame, and so the next time those two came after my dog, I let them have it.
The first time I was unarmed, and the owner was hardly any help to stop the fight. The next time they attacked, 6 months later, I gave the larger male a courtesy "tap" to see if that worked, nope. So, I gave him a full hit to his head, with the edge of the mushroom cap. All the force was concentrated in a small spot. He ducked down and ran home with his tail tucked. He may have suffered a brain injury, I didn't ask.
In the incident above, I was too close to expand the baton, so all it's weight was in the handle. Up close, it would be more lethal like that. Once expanded, the tip weight is the lightest ppiece of the three tubes. The reach, and tip speed, is why they are effective against animals' bodies, yet non lethal. Especially if the blow is spread out, vs concentrated like the mushroom's edge. Just my $.02