Flexi lock is an electronic lock that contains a micro-chip to control operation of the lock.
They look like ordinary credit cards, and contain magnetically encoded information which can be read by the Flexi lock. They are durable and do not get demagnetized under normal usage. Each Flexi card contains a unique 6-digit code. If this code is programmed inside the memory of Flexi lock, then when the card is presented to the lock, it will open the lock. If the number is not inside the memory, the lock will not open.