Ghost Firearms | Grid Defense offers premium AR15 parts with a focus on Cerakote Uppers, Skeleton Lowers, 80 Percent Lower and AR-15 Build Kits Ghost Firearms | Grid Defense offers premium AR15 parts with a focus on Cerakote Uppers, Skeleton Lowers, 80 Percent Lower and AR-15 Build Kits Ghost Firearms | Grid Defense offers premium AR15 parts with a focus on Cerakote Uppers, Skeleton Lowers, 80 Percent Lower and AR-15 Build Kits