They are parallel, not tapered. This has some definite effects we'll discuss ahead 4. They can be used with and without TFC's, swing bars, V-Bars, and other accessories. Let's look at the physics concept of inertia for a moment. Inertia is tied to the mass weight of an object.
Supertankers take several miles to stop from even a slow speed because of their tremendous inertia.
One important reason you use stabilizers is to increase the inertia of the bow as a system. By using a stabilizer, you are increasing the moment of inertia on the bow's vertical rotational axis. On the issue of these stiff light stabilizer rods, because they are light, they maximize the effect of any weight you use on the end of the rod. Earlier, we discussed the old-time finger shooters who would hold forever and shoot with a dead release. Today's top shooter wants that arrow gone in a short amount of time.