Hello, the pool coping was not sold by us on this project, just the stone veneer and pavers. But, by looking at the coping I can tell it's a Precast Concrete product. One manufacturer that comes to mind is Stepstone.
Precast is used a lot on pools with curvatures like this one. It can be cast in shapes based on a template. And, you can get clean curves and a nice finish.
Hope this was helpful.
Chris Gonzalez South County Rockery (408) 842-0022 chris@southcountyrockery.com
South County Rockery