The P38 can opener

The P38 can opener is a very simple device: a small piece of stainless steel with a folding curved cutting flap. In a naive approach you use this to open cans, unfold the flap pinch the can with the tip of the flap and in 38 cuts you will have the can opened and thus the name of the device.

But being able to carry this in a keychain because of its small size generated several other uses for the device. From cleaning nails to opening boxes cutting cord, etc. Some websites list hundreads of uses for the P38. Reatiling for less than a dollar a unit this is a vintage item that can be really useful.

You can learn more about the P38 in this website.