The bubbles on the Greenley layers are slightly smaller than any other layer I've seen. This gives you the opportunity to do the work even more precisely than on any other level. Also, the rope is a little annoying, but once you decide to rotate the level a bit so the cord doesn't get caught between the level and work, your gold. I have two and love them, the larger versions sometimes limit you on where to use them so having at least one is a must. They are actually more comfortable than you think. five stars