Protector your RFID or NFC cards such as a credit card from been read while in your wallet.

These cards have a small antenna and mirco chip embedded in them and can be 'read' when a scanner is held close by.
There are a number of advertised devises which will prevent a credit card been read by a scammer, but why buy one when you can easily make one yourself from an empty beer can. I used an IPA beer can but I think it will also work with a Pale Ale can.

The credit card protector is also useful when travelling on public transport that use swipe cards. It will prevent the possibility of having multiple cards charged for your fare.

The same principle works great it you need 2 swipe cards to access a building. Just seperate them in the same holder with a sheet from a beer can so they will each work.

Supplies

Empty Beer can
Sellotape
Craft knife
Scissors
Marker pen

Step 1: Make an Aluminium Sheet

Make an aluminium sheet by cutting the top and bottom off a beverage can, triming the edges using some scissors. Cut the loop open. Flatten it by rubbing the sheet against an edge.

Step 2: Mark Out

Place a credit card or similar on the aluminium sheet and mark out an outline with a marker pen.

Step 3: Assemble

Cut on the outside of the marked line, then assemble using sellotape. Cut a small cresent shape on into the open end to make it easier to slide a card out.