These are a direct fit for all Blackbird step over bikes. They stiffen the mounting point to the frame, eliminating both side to side and up and down flex. Some customers have had issues with not properly locking the battery down due to the cradle flex near the top of the cradle. These eliminate that issue as well.
Seems to work well . The cradle apparently has problems and is why I had to purchase a new cradle along with the stiffeners . That being the case I think the cradle should have been free if not both the cradle and stiffener. In any case at least the problem seems to have been resolved so at least thanks for that .
This product is actually being used on a different bike but it has the same cradle. It actually works great and stiffens it to the point where it doesn't move at all