http://money.o2.co.uk/summary.html tells you more about charges when using this card abroad.
I've just got one of these 02 Money Manager cards and in my opinion, its the best pre-paid card around, and I would seriously consider using it next time I'm in the Philippines. The main plus points for this card is no card issue fee (most if not all others charge £9 - £15), instant text message alert for all transactions, and no charge for loading money, plus UK transaction fee Free. Even some UK ATM withdrawals are free as well, otherwise its 2.75% for International ATM withdrawals. Unlike the Paypal prepaid Visa card, the 02 Visa card seems to behave like a full Visa card and is not an Electron Visa.