In this video i will show you how you can make your very own, very realistic matrix head-plug. If you cannot tell from the video you will need:
The bottom of a soda can
A smaller keyring or this piece off a flashlight i had
One of those pieces of metal used to hold insulation to walls (believe me, i spent hours researching to try to figure out what its called, so if i knew, i would tell you)
If anything is unclear, comment and i will update this post.