The Gaiyo Card can be used like a regular public transport chip card.
At the start of your journey, hold your Gaiyo Card against the pink OV-chipkaart logo on the gate or card reader. You are now checked in. The gate opens or the card reader gives a positive confirmation signal.
At the end of your journey, you check out by holding your Gaiyo Card against the pink OV-chipkaart logo on the gate or card reader again. The gate opens or the card reader gives a positive confirmation signal. You are now checked out.