I'm not going to go into details, suffice it to say that my back isn't in great shape. When it gets bad it gets very stiff and even stretching it is painful. Using this allows me to break through that stiffness while not risking further damage to my back.
Let me explain. While this is listed as a Shiatsu massager, I would say it's a light massage. Also the probes are widely enough spaced that they don't come in contact with my spine, just the soft tissue around it. This is very important. It allows me to break up the stiffness of my back without risk and without needing to see a physio or a massage therapist that day. It's made a massive difference to me.
What's good? It's battery powered. It can be put on any seat with a back that goes all the way down. It's gentle and can be heated. It has a soft flap that can be put in front of the probes to make it even more gentle. I've used it every day for about a month now and it's showing no signs of wear.
What's bad? If you use heat and massage at the same time the battery lasts less than 1/2 an hour. I'm a big lad (6'5") and I can hear it creak when I lean back on it. I'm not convince how long the mesh in front of the probes will last.
Summary: This has made a significant difference to my pain levels over the last month. Even if it only lasts a few months it will be worth every penny and I will buy another. It's convenient and it works.
Recommended.