So, this capo is exceptional at what it does. It is designed for fretting individual strings for unique tunings. Some things I want to address that I have seen in other reviews are as follows (my testing was done on a classical guitar):First, damage to the guitar neck/bridge. It won't leave any kind of marks unless you overtighten it. This isn't a woodshop project, the clamp doesn't need to be exceptionally tight to function. When it is fastened properly, it is sturdy and the padding is more than enough to prevent any kind of scuff marks.Second, the fretting mechanisms and bending strings sharp. It definitely can bend them sharp on the lower strings, but the fix is to simply engage the fretting mechanism less so it isn't pushing the string down as aggressively. Each individual fretter is relatively stable in every position I tried, so adjust by ear to your needs.Third, the construction. The thing is way more durable than I anticipated it being. While I won't test it for my wall's sake, I am certain I could throw it at the wall out of anger and it would be unscathed. My wall would be a different story.Final thing is fitting it on the neck. It fits well, just adjust the width. It has a deceptively accepting size range for necks. It works on my classical guitar, and it looks like it would work for any 6 string by design (given the 6 fretters). It likely would work on some extended range guitars (clearance looks large enough for a 7 string and possibly an 8 string, but I don't own one to personally test it on).Definitely worth giving it a shot. Opens a lot of doors for interesting experiments for guitar for sure. I'll update my review when I have tried it on bass.

Neat tool to try some new "tunings." That being said, this isn't something you can throw on real quick in between songs when playing live. The design is a little clumsy, I wish they would have put a spring inside because removal is a little awkward. But one you place it correctly, push down the strings you want fretted, then retune because it will knock it out of tune, it does what it advertises.Great at what it does, just a little clumsy

I am not a big capo user. Strictly as a capo, I would say this is somewhat awkward to use. It cannot be easily slapped onto the neck for a quick key change, but I assume most people would not be buying it for that reason. It's appeal is the ability to capo only specific strings at a given fret, allowing the un-capoed strings to be played with their natural open tone. One ought to expect some degree of difficulty in achieving this more advanced level of capoing. It is important that the individual string blocks be slid to the correct position above the strings. That isn't hard to do, but if one is careless in this adjustment, the block will not come straight down on top of the string. If that happens, there can be buzzing, or the string may be pushed slightly to the side, resulting in a pitch change. On several guitars, including both a wider necked classical and an electric, I was able to fit it to the neck, and obtain a cleanly capoed sound. The classical neck extended it to its limit, but it still did do the job it was designed to do.One important point about its use for alternate tunings, is that it does not actually change the pitch of any of your strings, so notes that you play on frets above the capo will have the same sound they normally would, and not the sound they would have if the guitar were actually re-tuned in an alternate tuning. In other words, if you like to use an alternate tuning to play slide guitar, this device won't help at all. It is still, just a capo in that respect. I would say, that limits its use in experimenting with alternate tunings. I had been wondering about experimenting with using an all 4ths tuning (E-A-D-G-C-F) so that all patterns could be moved without having to allow for the 3rd interval between the 2nd and 3rd strings. I realized that the SpiderCapo could not assist me with that.I do like experimenting with high neck open-stringed chords, and it has its benefits for things like that. Also any song that require the use of open drone strings can benefit from this capo. Some of the chords obtained in this way can be quite beautiful, and I don't really know of any other way they could be achieved without one of these. For example if you capo some of the notes at the fifth fret, and then play up at the 12th, Its possible to let those 5th fret capoed string to ring out clearly. You would never want to do an altered tuning that stretched a string to achieve a sound that high You would most likely break a sting if you tried--not to mention the added stress on the neck.Another positive for the capo, is the ability to flip any of the string blocks up or down during a song if you want to. I don't know of anything else that gives you that capability.It is a unique capo and has some specific unique advantages and enables playing techniques not offered by other capos or even by the use of alternate tunings. On the other hand, if what you are looking for is an easy way of achieving an alternate tuning, that's not what these capos do. If you get it for the wrong reason, you will be disappointed with it.