Ok, back in the old days, in the dusty recesses, tires all had inner tubes. If one was a bit clumsy, you could let the valve stem slip back inside the tire, which would bring on shocking new words. With this tool, once the first bead of the tire is over the rim, and the tube inserted, this was threaded onto the valve stem, to hold it and keep from slipping inside the tire. This was a job that was really tough on the manicure too. Could also have been used to pull new valve stems into tubeless tire rims. The ones I had, were attached to chains, that had a toggle, that prevented loss inside the tire. I'd still like to have one again. Neat tool.