Yet Another Bottle Opener, Customizable

What it is
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A Bottle Opener that is
* easy to print (No support needed)
* designed to dent the bottle cap in the middle for easy opening while being as small as possible
* using a coin to avoid that the opener is damaged by the bottle cap
* having the coin press-fit into the opener, no glue needed
* designed to be held with either the index finger or the thumb
* either attachable to a key chain or can be printed without the key chain holder
* flexible with a fully customizable coin size to be able to use any currency, "1 Euro cent" and "1 US Dollar cent" are already configured and rendered to .stl
* nice to handle, all edges are chamfered with the library [Chamfered primitives for OpenSCAD](http://www.thingiverse.com/thing:1305888)
* printable in roughly 2 hours (If you use a Euro 1 cent coin)
* also a nice toy to play with while thinking

I am thinking about building a whistle into it also, there should be enough space for a high pitched whistle alth