The Calgary Flames Hockey Team hat.
He wore both a white and a black version. Now these style hats that he wore are generally an 80s style, and they don't make them anymore. I did however find a white and a black style, which is the most similar to the show. You just can't get the same kind of hats he wore, even on ebay. It was hard enough finding these hats but here they are:
THE BLACK CALGARY FLAMES BALL CAP
Not an easy one to find, I would suggest getting yours before they go out of production. You can find them at http://www.lids.com/pid/20037691for about $25. You have to measure your own head to determine the size. Most all other black Calgary Flames hats have red trim or other logos on them.
THE WHITE CALGARY FLAMES BALL CAP
A solid white Calgary Flames baseball-type hat is even less easy to find. A long and hard search came up with one which still has red trim around vent holes in the top of the hat, but it is the closest thing I've found to even a plain white cap with the Calgary logo on it. Believe me, try and see if you can even find one on ebay yourself! http://www.cupstuff.com/nhl/calgary/cfwpfc_m.htm
Macgyver's white hat is basically a 'trucker' type hat with plastic mesh backing, and snap closure. Your best best for an actual replica is to find a "C" Calgary Flames Logo patch and stick it on a plain white trucker hat. These are more modern
than Macgyver wore and are not quite replicas, but does he really, or anyone, look good in a hat like he's wearing? The hat looks pretty good in Trumbo's World:
Stay tuned for more MACGYVER GEAR Updates. I am tracking down the most useful and popular gear that Macgyver used in the show.