D'Addario Planet Waves Capo Lite Black

Well made and good value for money

I now have one of these for each of my guitars and a couple extra. They are really lightweight and unobtrusive. Even though it probably wasn't the intention, they are easy to fit with one hand and adjust the pressure just enough without messing up the tuning. They fit all my guitars (acoustic and electric) with nut widths up to 44.5mm, but do not work on a couple of my electric guitars that have very slim profile necks. You wouldn't normally use a capo on an electric guitar with that type neck anyway.

Guitar capo unsuitable for mandolin

Well designed and doesn't obstruct the fretting hand much at all. Allows you to adjust pressure just enough to avoid buzzing strings but without squeezing them down unnecessarily hard and raising the pitch another quarter tone, as many capos do, and you then have to tweak the tuning. Can be applied and released one handed with some practice, but a little tricky to begin with. In the real world what guitarist can't take 2 seconds between songs to use both hands, so I don't see that aspect as important or relevant to me.