They want five bucks for this. If only there were a way to do this more cheaply with materials on hand (like a nut, bolt and washer).
https://youtu.be/XmDFAHXbrNY
I save empty spools to do that. I use a threaded rod in the spool. Rudy
I use empty spools too. many of them fit snug on a 1/4" hex bit adapter. I've also been doing the thing with the bottle lid on 2 liter bottles for a long time, Just do one lid, then reuse. I hope the fellow didn't invest in patenting and manufacturing.
I use pop bottles for line I am going to discard...just drill a hole in the center of the cap, and use a 1/4 screw,nut, and a washer, or two...you are thinking righr...don't spend big money ! I use a screw that is all thread", and just tighten the chuck onto the threads. If I want to save the line, I'll put it either on an empty line spool...or on an empty spinning reel spool.