Yes it is possible to return your old and used interface for an UPGRADE.
Here are the conditions:
Purchase the UPGRADE offer available from our store and choose witch product to upgrade (DVC2 512, DVC2 GOLD, DVC2 IP, DVC2 GOLD ZM).
Return your old interface with a copy of the invoice and the payment, this interface must work fine.
If the return interface do not work, we will charge 70 euro for repair (notincluding the VAT)
After payment done we will send the new product for upgrade.