Do you want to install the Pannier Stabilizing Insert in your bag, but your bag doesn't have a prepared internal stiffening because it's a model from 2023 or earlier? No problem! With the Retro Fit Kit Stabilizing Insert, you can easily retrofit your bag yourself. For QL2.1 reuse the T15 screws from the lower rail to mount F3912 Retrofit Kit. For QL1 and QL2 reuse the screws and screw nuts from the lower rail to mount F3912 Retrofit Kit. Even bags with the QL3.1 mounting system are not an issue. Simply contact our customer service, and they will help you customize your bag accordingly.