I love this roller. The 18 inches is a perfect length. The foam is the right density. This is a great tool for anyone in chronic pain.
If you are not familiar with foam rollers, there are a bunch of helpful videos on you tube that can show you how to use them. You can also ask a trainer at your gym to show you how to use them. They are a great way to address muscle tension and pain.
I won’t lie, there is a learning curve to these. When I first started using them I felt like I was just flopping around on the floor, but with practice I was able to figure out what was helpful for me. The biggest benefit to a foam roller is that they are really low risk. It is unlikely that you will have any harm come from trying one of these out.