Imperial Comlink
As seen in Star Wars Episode IV - A New Hope.

Let me start off by saying that this was not an easy project to accomplish for such a simple looking prop. I started by lookig at the image in the Star Wars Visual Dictionary and by looking at the film. Once I had an idea of what this prop was I bought my supplies to make this project.
I measured and cut my pieces for this project and my work began...
This is the end (bottom) of the Comlink. You never see what the bottom looks like so I improvised.
I used the bottom of a big magic marker and glued it into this piece.
This is the middle of the Comlink where the black O-rings are. Since this piece is larger I glued some cut pieces of a zip-strip so the unti will remain round when the O-rings are placed.

Here are the pieces zip-strip pieces glued on. I then glued it to the bottom piece and added black electrical tape to hide any white that might show after the O-rings are placed on.
Here are my pieces next to a copy from the Visual Dictionary.
You see how I tested to see how the O-rings would work.
Here is the voice pickup. I found this (very hare to find) part in a bag of parts from a Kitchen Sink hose kit. I had to cut off the threads that were on the bottom of this item. I then added in a sink screen and part from an aireator.
Here are the parts taking shape.

Here is the Comlink taking shape after all the pieces are glued together.

Now it is time to place on the O-rings.

Here it is, my finished Imperial Comlink.

Here you can see the "Top" and "Bottom" of the Comlink.

I hope you enjoyed my progress of this project.