This chair seems it was coming apart and someone tried fixing it with a staples. Once it was sat in and stretched you could see the staples and they were poking my butt.
This is a great home office chair. I tested less expensive models in store but opted for this one because it was firmer and rated for 5+ hours of sitting (the mid-tier). I prefer mesh to cushion seats. The back also has a small amount of lumbar support. It was fairly easy to assemble myself with a hex wrench but the casters require a little bit of strength to install.