This picture was sent to me by Karel Menard. It came from a Canadian soldier who was trained in Canada during WWII, but was never deployed overseas.
This gas detection brassard looks identical in shape and construction to the British made ones, but the colour is more dark brown and the stitching is brown instead of white.
What mainly stands out is the different stamps on the inside. It is marked with a logo in an oval with a J, R and C? It’s hard to make out, but presumably, this would have been the manufacturer. The date stamp is NOV 13 1942. There’s also a Canadian broad arrow stamp on the inside, not visible on the photo.
These Canadian brassards are quite rare. More so than the British made ones.