Chipolo CARD

"Let Chipolo CARD keep an eye on your wallet and never worry about it again. Use the Chipolo app to ring your misplaced wallet or double press on Chipolo to find your phone. Get a notification from the app if you leave your wallet behind. When it’s not around to ring it, you can always check the app to see when and where you last had it with you. Chipolo CARD is as thin as two credit cards, which makes it fit your wallet perfectly. But you can also slip it into your passport pouch or attach it to the remote control."