Sewmuchmore, I have just almost turned the chair upside down to have a good look at the arm. An ordinary zip has been used, one side has been stapled into the wood whilst the other side is sewn into the arm fabric and padding. Also the way they have put the zip in is that the zip pull is well hidden and tucked away, so if you can imagine this the zip is inside out. I would probably break a few finger nails trying to get the part of the zip pull moving.