GS Lanka produces all North kites and North surf sails. This is by far their main production. Our kites are manufactured there as well, Zian founder has been the CEO of GS Lanka for 5 years till 2012. Core and Best are not produced at GS Lanka as far as I know.
North windsurfing (sails? if that's what you're thinking) and North kiteboarding are one and the same company (Boards & more) but they have Nothing to do with North Sails (the yachting guys).
North Sails sold off the windsurfing side of the business years ago and the Sri Lanka factory even changed name later from North Sails to Global Sports to open up as a generic production facility, which is what they currently are, producing kites and windsurfing sails for many different brands.
The North Sails yachting guys are in a different league altogether and couldn't be bothered with piddling around with kites