I don't throw much away, which is good and bad...
But sometimes I find some interesting things because of it. Like these things:

After finally remembering what they are called, I googled them and found this auction.
It would seem I am missing a set of pistons. The next time I monkey with an old RC10, I am going to throw these turkeys in.
What they do is make the shock progressive. The tapered stinger slides through the piston hole, making the shock stiffer as it is compressed.