I've been playing Half-Life 2 lately and decided to work on a combine costume so heres how to make it!
you can find how to make the stun baton at this link:
To start you will need a PMG gas mask I found mine in Sz large on eBay at this link:
Next you will need a black long-sleeve shirt and a white T-shirt to put over it. Next pull up the edge of the white T-shirts sleeves and glue them to the shoulders.
Now all you need are some gloves, boots, a belt and a vest and wa-la, your'e a combine!