I bought the Shubb C1 for use with both electric and accoustic guitars and so far as the electric guitar is concerned, I love the design, it has a good quality feel and it performs well.
However, I have one criticism, certainly concerning the website description (..if not the design), which states that it is good for electric/accoustic guitar.
In my view it is only good for accoustic guitars with the more slender profile necks and the description should be changed accordingly. While of course there can be considerable variation in neck cross section, I have an electro-accoustic with a neck that is basically as per classical guitar and the rubber sleeve which presses the strings is exactly the same length as the distance across all six strings (50mm), which does NOT work. I feel slightly let down and find it most annoying when there's absolutely no reason why the metal component wouldn't allow the rubber sleeve to be just a couple of mm longer, which would then adequately fulfill both functions. In my view it is only suitable for a string span of ideally 46mm or 47mm at most. Why can't this be stated?