No, this is not a fold-out light saber, stacking rings for kids, or some erotic device. It’s the Fein 921072K13 Step Adaptor, on sale at Coastal Tool for $3.75.
The Step Adaptor is for connecting the Fein dust extraction/vacuums such as the Turbo III to a variety of hoses and tools. You simply cut it to the step that fits your tool. Looking around it also seems to be the least expensive of any available vacuum step adapters, so we wonder if it can be used with other makes of shop vac. It’s also available on Amazon for $6.15.