I previously had 2 spider capos about 5 years ago and they had great potential as the catalyst for yielding very fruitful creative output. unfortunately, they were lost and I had some unfortunate turbulent, traumatic years where I so wasn't in the position to be creative.
Thankfully, this period of my life is over (it's just the small matter of the whole world that's under duress now...)
Anyway, last year I bought a few Chinese spider capos from eBay last year which were a lot cheaper. The 1st 2 weren't as good as these of course and very awkward but actually usable, but I gave one to a friend and ordered another one, but it was TOTALLY unacceptable because the thread of the screw wasn't long enough for coverage of even a 43mm guitar nut. I couldn't get my money back and was of course loathe to buy any more of the cheap Chinese versions of this product. So after a while, knowing the potential of these products I went 'back to Daddy' as it were and invested in 2 of these proper ones.
Why 2? Well, there are so many combinations of open chords you can make with more than just one.
The thread of the screw on these is just about suitable for 52mm nut, full size classical guitars.
With careful positioning I have also used these on 12 strings, which sounds great, and takes the hassle out of open tunings on a 12 string!
I would stress, to be helpful that I have found these spider capos aren't great for a more curved fretboard like a traditional fender type.
I look forward to getting a 7 string soon and using my spider capos on that.
If I get an 8 string, then I will definitely be buying one of the XL versions.
Brilliant product. I see these almost as a trade secret for creative innovative players, which I altruistically, yet reluctantly encourage to explore.
Just make sure you DON'T buy imitations, you will most likely get ripped off with something that doesn't work or at best have a greatly inferior product.
Also, make sure you are using it properly when you 1st get one, before grousing about how it doesn't work, as even I have heard a professional admit, who in his excitement, didn't follow the simple, basic, straight forward instructions. Their website is very helpful and has many suggestions for various positions of tunings.
Thomann has the best price I have seen for this product. It may seem a lot for a capo, but I think these are worth far more than their weight in gold. Such fun to explore new possibilities.