the Runners Mace.
This is a self defense device that is 12 inches long weighs 4.35 oz or 124 grams. It is made of military grade 550 cord wrapped into a monkey fist that covers a steel ball weighing 2.35 oz or 67 grams. It also comes with a 5 inch steel rod that can be used like a Kubatan.
If stricking a potential attacker with the steel ball doesn't detract them, them jamming that rod into their face, side, leg, or across the forearm will.
It fits comfortably in the hand and will not impede your running form.
Oh yeah, it also has a pacer beads built-in to let you track how far you have run.
Finally, they are currently available in about 7 colors, with more to come.