The purchase price is due immediately after receipt of the goods without deduction. The customer can pay via credit card, advance bank transfer, immediate bank transfer, cash upon delivery or direct debiting. If the customer comes under delay of payment we are authorized to bill interest amounting to 5% above the respective base interest rate of the European Central Bank (EZB) as of the corresponding point in time. If we prove a higher damage of delay, we are authorized to enforce it. The customer on his part is authorized to prove to us that no damage or a significantly lower damage occurred to us in consequence of the delay in payment. The customer only has the right of offsetting his counter-claims if they are legally confirmed or if weacknowledged them in writing. The customer is only authorized to execute a right of retention if his counterclaim is based on the same contract relationship.