These are modifications of the standard trackpad but sit on a rubber base. The 4 bolts that hold the pad on to the chain hold the pan to a thinner base plate. This plate has a backing plate also trying to make it is as strong as the originals.
Unfortunately it isn't as most plate have a slight bend to them outside of where they would have bolted to the chain.
I got 56 pads a a good price and 2 originals. As you can see they have been used.
Below is a picture to show you what they look like. I do not know who the manufacturer of these aftermarket pads are.
Bill
