The watch band is a perfect OEM fit for my G-Shock Giez GS-1100 [4777].
I removed the old band with a sharp razor blade. This exposed the ends of the screws that hold the band in place. To remove the band retention screws you need a small but strong Philips screwdriver; my first screwdriver's tip broke off. The threads are set with a loc-tite type thread compound, and you need firm pressure and a good grip to get the screws to back out. Be careful not to round out the screw heads. It is possible to remove only one screw from each half of band and slide the band off of the smooth end of the screw shaft. This method is preferable to removing both screws.