The can of unique has been opened. Unopened cans have a metal tab and ring around the cap when they are unopened. To open the can you push down on the center of the lid and the flange flares out and you can lift of the top. The H335 is from the late 70's early 80's. The Unique is from the 60"s. I'm still loading powder out of cans like that. Way back when I was shooting registered trap and as a group the teams bought quite alot for our own use. I had a friend who I shot with and he passed away 30 years ago. His wife passed away about 2 years ago and her son found all this powder that he had put away. So he gave it to me because he knew I still was reloading. Nothing wrong with it no acidic smell and no brown dust. Hercules is very stable powder.