Sorry but it's printed right on the cards what you can redeem them for.
$10 USA and Canada cards can be redeemed for 1 month of Prepaid time or 5000 Crowns. $15 Australia cards can be redeemed for 1 month of Prepaid time or 5000 Crowns. $15 New Zealand cards can be redeemed for 1 month of Prepaid time or 5000 Crowns. $150MXN Mexico cards can be redeemed for 1 month of Prepaid time or 5000 Crowns. $20 USA and Canada cards can be redeemed for two consecutive months of Prepaid time on the same account or 10000 Crowns. $29 USA card can be redeemed for 1 month of Prepaid time or 5000 Crowns. $39 USA cards can be redeemed for 1 month of Prepaid time or 5000 Crowns.
