Beijing Transportation Smart Card is similar to a store value card?

The card is similar with the store value card. It is lent to users for free. You can apply one card at the airport and you can also return it at the airport. I know there is office to return the card in T3. Well, if you apply the card for the first time, you should put down a deposit of CNY20/card and add some value of no less than CNY20. The full deposit and the balance in the card could be refund. No hidden fees or service charge in using this card later.