You can look at the sides of the body. If there are three rounded sections without knurling, then it might be one of the newer bodies. The older ones had flat sides.
Try to stuff an 18650 lithium ion cell into it. If it fits, you're holding old stock. :lol: If the 18650 won't fit, but there's a black plastic sleeve inside the tube, it isn't the most recent generation.
Does it matter whether it's new stock or old? I think in some ways, the old ones were better. It's probably more important to turn it on, and see if you like the tint and the donut. I wouldn't worry whether it's from the latest batch or not.