If you search utube for "Federwinder" you will find the video. It appears that the embed feature for this video doesn't work.
The winder has many features of an Ollie Baker. One interesting thing is that it uses a cloth strap to restrain the barrel while the spring is being wound...you don't have to hold the barrel with a gloved hand.
Looks like a pretty nice solution to removing and installing springs in barrels. Loose springs too. I have had several different types and have found shortfalls with any and all of them. This one looks like the best solution I have seen to date. And yes, I have had what was supposedly the "best", the very expensive Bergeon. Ended up being one of the least used of the several spingwinders that funneled through, but it had some good points too. Just was not sad to see it go.