[LyquidFyre]

There was a recent posting that lists all prohibited items from importation.

http://www.airsoftcanada.com/showthread.php?t=51297

And there's also an FAQ from a few years ago with a more detailed listing.

http://airsoftcanada.com/showthread.php?t=40318

Unfortunately the silencer/suppressor is on the prohibited list. If someone managed to get one in, that's purely luck. Just search for "Prohibited items" and you'll probably pull up a few more threads.