This is the original self-retracting key holder, still made in USA.
It has a 1 1/4" split ring on a sturdy 24" long stainless-steel chain, housed in a chrome-plated steel case. With a strong return spring, it can hold tools weighing up to 10 oz or about a dozen keys. It conveniently clips to a belt or pocket, or inside a shoulder bag or backpack.
Measures 2" in diameter.