This kind of matter has never happened to us before. But if it happens and it is our fault, we pay all the cost without any bargain.
(2)Who pay the cost of modification?
The small changes are free. But for the great changes, if it is our fault, we pay; customers’ fault, they pay; both fault, share it balancedly.
(3)Do you make spare part for customer?
Yes, we do. If customer request .