Wow, that is some spider! :)
I ordered the mini and it arrived yesterday-loving the flexibility of changing to all sorts of tunings quickly. It fits great on all the fingerboards I own (checked before ordering) The "fingers" can be removed easily and made to fit even three string dulcimers. Please continue your comments as you try this-I am curious how everyone feels! I currently have one finger fretting both melody strings and it is the clearest sound I have found while experimenting! (see photo)
updated by @hewalker: 10/23/17 06:25:00AM
According to the web site the spider capo mini should work on mountain dulcimers. “The Mini SpiderCapo is for narrow necked instruments. These include, but are not limited to: Banjo, Ukelele, Mandolin and Bouzuki.
Users report that because the SpiderCapo clamps over the fingerboard, and not behind, it can also be used on the Mountian Dulcimer.”
I looked at their site earlier today to see if they published any specs. I couldn't find any. I I wanted to find out what the open width is [ 1 3/8 to 1 5/8"], if the fingers are sideways adjustable so they can be placed over different string spacings and if they work on flat fingerboards [I don't use any of the instruments they make them for]. They also offer custom made. If they will work oh MD's , there could be a lot of unique tunings done.
I had never heard of the spider capo, so after looking it up, it is quite similar, but probably better, than one called "The Extra Hand Capo." I had (and still have) one of those and it was really cool experimenting with the different strings held down with open strings. Even tho' I don't like capos (they cut off too many frets) I might have to try one of those.