No idea I’m afraid. It’s stamped as a Z22 but it is made from silicon and has a metal keeper rather than rubber. I don’t know if all Z22’s are this spec now?
This one came on the watch in the photo, which is a limited edition for the South East Asian market only, so not sure if the straps are readily available, but you’d like to think that a replacement would be marketed for the watch owners.
Whilst looking for it on line I saw it referred to as a Seiko silicon snake-belt strap, but again, I don’t know if that is a thing.