Here are a couple of different inductors. This is the long cast inductor used on the standard non SV spool. Notice how the very end is beveled, this makes the braking force weaker. Additionally, the spring under that inductor is stronger than what's found in the SV. The inductor works on centrifugal force. When you cast, that spring moves the inductor outward into the magnet assembly slowing down the spool. Next we have the SV inductor. The SV inductor has no beveled edge, and it's also a good amount longer. Paired with a weaker spring, this gives much better braking but at the expense of distance.