You can use this card to pay at designated convenience stores, food courts, or vending machines without needing cash.
Octopus cards can be reloaded with cash at thousands of locations across Hong Kong (7-Eleven, Circle K, 759 A-Sun Store, McDonald's, VanGO Convenience Store, Watsons, Mannings, etc.).
The unused balance on the card can be refunded in cash at any MTR station (except the Airport Express counter).