This is an Easy secret safe used to store your microSd card ,password or any sort of thing....And i got this idea from a youtube video. I will post the link as soon as i gets it.
Step 1: Things Needed
Step 2: Procedure
Take the two coins and place it on top of each other and solder it so that there is a space between 2 coins..
You can shave the coins if u want to reduce the Thickness.
Step 3: Done
... Yes its done, After the solder has been dried you can place any small thing in the coin.