GT Kraft offers high-quality dyno-tested tuning files. After signing up for a GT Kraft account, you can buy our ECU tuning files. Our GT Kraft credits pay for files. Customers can purchase credits with a credit card, Paypal, Bitcoin, Alipay, iDeal, Sofort, and many more payment options. All credit sales are final. We do not restitute money, but we do refund credits when it is deemed appropriate. After purchase, tuning files can be downloaded to your secure GT Kraft account. For support, contact us on Skype or Whatsapp.