[Stocker]

I haven't seen those in decades. They used to be, in theory, a poor man's overload system. Help your truck (or car!) carry more weight, or compensate for worn out sagging springs. Toss 'em with no regrets.....

EDIT: just saw the above post. I had no idea they were still made. Ones I was thinking of were aftermarket add-ons to go on regular shocks.