Here is an extremely nice challenge coin of the Canadian Army.  It features the colours of the 5 Canadian divisions, Red, Blue, French Grey, Green and Burgundy.  There  is also a great jump scene image on the reverse.  It's a weighty coin at 45 grams, well over 1/8" thick and 2 3/4" or 43mm wide. 

The edge is sliver and I suppose it could be engraved if you chose to do that. 

Good luck and thanks for looking at one of The Mighty Atom's sales.