One of my sisters gave me a gift several years ago. It is a leather wallet that has two pockets that are sized to hold 3x5 cards. One of the pockets has an open face so that you can write on the top card, the other has a closed face so that you can carry lots of extra cards.
It is indispensable.
It is embossed with the text "Gerber Safe Company". Other than the fact that I own the wallet I have no connection with them.