The G650 is the latest and largest bizjet from Gulfstream Aerospace and has proved quite popular with over 400 units sold so far.
Gulfstream Aerospace G650 for KCAI model
This package includes 4 G650s operated by Gestair.
These textures are intended for the KCAI Gulfstream G650 model available here.
G650 Flightplans by Danny Jones (and including these airframes) are available here.