Foam blocks, softer than cork, but still work well. This is a set of 2 blocks, and it comes with a strap, handy for shoulder stretches and heart openers. I don't have a picture, these are some of my old blocks, but the Syntus deal I put in this link is just a very good deal with the addition of a strap too, which can be very handy for some poses, again not a necessity at all though.