Rain Poncho for GoPro Hero3 mounting frame

Rain Poncho for "GoPro Hero3 mounting frame" ( http://www.thingiverse.com/thing:76082 ).
I developed this model for these requirements:
- Mounting system must be light as possible. (for helmet mount use)
- Splashproof function is needed only in rainy condition, and must be added easily.
- USB port must be accessible. (for all day use)
USB covers for genuine combo cable(dia 5.8mm), common cable(dia 3.8mm), and thin cable(dia 2.5mm).
You need to embed a transparent plastic plate (4cm*3