DMI Lumbar Support Pillow

The shape is fantastic, it fits perfectly on my back. I am female though so obviously if a larger male tried to use this I can see how it might be too narrow to fit comfortably. I say this because it's hard to tell from the photos but the pillow is actually concave from side to side. So if the thickest points of that were actually on your back instead of to each side like they're meant to be, it might defeat the purpose of improved posture. The strap is a useful idea, but in execution it's actually quite poorly constructed. They used a crappy piece of elastic and sewed it to each end. When it stretches around my (normal sized!) office chair, I can tell that it won't last long like that because it is pulling at the fabric lining of the pillow itself, and that fabric does not feel durable enough to handle being pulled like that for very long. It should be re-designed to be a more durable strap with something like a velcro closure. That way, it can easily accommodate any size chair, and not feel like it'll pull apart at the seams or snap at any moment. If it breaks I have the skill to fix it myself--but I know a lot of people either wouldn't know how or wouldn't care to try to fix it--so if that sounds like you and you're not using this on a children's chair, I would look for something with a more durable/adjustable strap.