Vintage Chemistry Rings good and Clamps

Great collection of Vintage Chemistry Rings and Clamps. All secured on a chemistry stand. The only good part missing is the base.
There are 5 rings. All have varying degrees of rust on them. One screw is marked Cenco. The others appear unmarked. Still very cool. There are 3 test tube clamps. They are clean and without rust. One is marked Fisher and the other two are marked Precision.
Fun Vintage Industrial Find!