Jim Dunlop Deluxe Professional Toggle Flat Classical Guitar Capo 15F

This works perfectly well. It will adjust to any classical or flamenco guitar neck. (If you have a steel string guitar, look for the curved version of this capo.) What I like best is that it is compact and very easy to carry because it fits in any pocket.
Even if you prefer a capo with a lever, I suggest you get this one as a backup and keep it in your guitar case. It is so well-priced!

Works perfectly and easy to use.

While being one of the least expensive capos for classical guitar, this could very well be the best. Here's why: First - This capo clamps extremely well, and evenly across the strings - not every capo can boast this, especially some of the more expensive ones that can clamp better on the bass side than the treble. Adjust it right, and you can play as hard as you like without buzzing (depending on your guitar, of course). Second - and of equal importance - is that all there is behind the neck is a flat nylon strap. Many capos have grip handles, or a mechanism of some kind that sticks out to one extent or another in the way of the hand. Third, this capo is very adjustable - you can get it exactly how you want it. Here, though, is my only gripe about it, and that is that the stiff nylon strap and can bit tricky to adjust, using the buckle - but this is a minor annoyance. When you add the cheap price, the low profile, light-weight design, this is a bargain and a half. Watch Siccas guitar and GSI videos on YouTube, and you'll see many players using these Dunlop capos. Highly recommended!