I bought this after trying one of the simple converter cables that sell on Amazon for about £4. From what I've learned by now those cables can't possibly work, as the outputs of VGA are not what composite or S-Video takes in.
This box however, does a proper conversion and works alright as such.
Despite coming from Germany I received this after just 5 days from dispatch.
The instructions were in English, so no problem with that part either.
Upon trying it with my PCs and my ancient Sony 29" CRT TV, I found that using S-Video worked as such. However depending on activity of the PC it often had "stutters", were the screen went briefly blank and then continued. (hence 4 stars)
Using the composite output worked fine though. Thankfully the screen quality is not significantly worse with that.
Be warned though that reading anything at a resolution of 800x600 is challenging, but as noted this could be down to the age of my TV.
The box allows for size and position adjustments, which I've found useful.
So altogether defintely worth the £15 I paid, especially given that most others want £30 or more for similar/identical looking boxes.