No, aftermarket. You can't find a NOS since the early 90's. Casio wasn't expecting right after the 5600 that G-Shocks would become collectables, so they didn't plan much ahead in terms of spare parts. They thought that with the new releases people would simply trade their watches if the resin got wasted, so they just didn't have that many spares produced. The interesting fact is that more then probably a good aftermarket resin would outlast an original one because of the composition of the PU resin - that's why modern resin will last longer then the original ones.