Don't know what a Corbin looks like underneath, but the whole idea is an L-shaped bracket that bolts under the pillion and on the back of the backrest cushion itself. I used a home-made cushion to start with, but ended up using the one that is used on the passenger backrest. Got one from another member here. I like the support in my lower back - feels just like a steady hand supporting it - and the looks aint bad either...
